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1
Jindra, Jakub. "Entita." Master's thesis, Vysoké učení technické v Brně. Fakulta výtvarných umění, 2014. http://www.nusl.cz/ntk/nusl-232401.
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Informace může vytvářet určité entropické krajiny. Entropická krajina je složená ze zdrojů informace. Zdroj může být informačně přínosný nebo úplně zbytečný. Dobrý zdroj vytváří nízkou entropii, vysoký náboj, a špatný zdroj entropii vysokou s nízkým informačním nábojem. Touto optikou pak můžeme vidět fiktivní krajinu, která se kolem nás nalézá. Entita je její vizualizací, vytváří útesy, tam kde byly roviny, hory zkoncentrované informace a měsíční údolí s nulovou hodnotou.
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Bradbury, James. "Computational hypothesis generation with genome-side metabolic reconstructions : in-silico prediction of metabolic changes in the freshwater model organism Daphnia to environmental stressors." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8437/.
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Computational toxicology is an emerging, multidisciplinary field that uses in-silico modelling techniques to predict and understand how biological organisms interact with pollutants and environmental stressors. Genome-wide metabolic reconstruction (GWMR) is an in-silico modelling technique that aims to represent the metabolic capabilities of an organism. Daphnia is an emerging model species for environmental omics whose underlying biology is still being uncovered. Creating a metabolic reconstruction of Daphnia and applying it in an environmental computational toxicology setting has the potential to aid in understanding its interaction with environmental stressors. Here, the fist GWMR of D. magna is presented, which is built using METRONOME, a newly developed tool for automated GWMR of new genome sequences. Active module identification allows for omics data sets to be integrated into in-silico models and uses optimisation algorithms to find hot-spots within networks that represent areas that are significantly impacted based on a toxicogenomic transcriptomics dataset. Here, a method that uses the active modules approach in a predictive capacity for computational hypothesis generation is introduced to predict unknown metabolic responses to environmentally relevant human-induced stressors. A computational workflow is presented that takes a new genome sequence, builds a GWMR and integrates gene expression data to make predictions of metabolic effects. The aim is to introduce an element of hypothesis generation into the untargeted metabolomics experimental workflow. A study to validate this approach using D. magna as the target organism is presented, which uses untargeted Liquid-Chromatography Mass Spectrometry (LC-MS) to make metabolomics measurements. A software tool MUSCLE is presented that uses multi-objective closed-loop evolutionary optimisation to automatically develop LC-MS instrument methods and is used here to develop the analytical method.
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Auton, K. A. "The oxidation of methylamine by the obligate methylotroph, organism 4025." Thesis, University of Southampton, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233262.
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Králík, Martin. "Červená královna." Master's thesis, Vysoké učení technické v Brně. Fakulta výtvarných umění, 2016. http://www.nusl.cz/ntk/nusl-240613.
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Red Queen is a chess piece on the story of Alice in Wonderland, which is constantly running to hold it in place, because the world around it is constantly in motion. Therefore, it is a symbol of the theory of evolution, a constant necessity innovation and the eternal escape from competitors. Red Queen's Race is constructed into a miniature civilization, or rather one growing superorganism, which constantly oscillates between the digital and the physical world. The main consciousness of this association is black majestically looking server that supplies with his computing power and energy all attached printers. They are designed specifically for this purpose, such as abstraction of robotics industry, with an emphasis on a functionally aesthetic form, in yellow-orange color of heavy industrial machinery. The most important and largest part of this system, are entities which printers materialize. They are created according to a living creature of this world, generated by computer, based on a unique code, which is the result of calculating the evolutionary recombination, processed by the server, depending on the reactions of outside observers at the objects which are already created. Sense of each entity is attract attention. How much more, the greater is the chance to continue their code in future generations.
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Modin, Judit. "Synthesis and Evaluation of Photoactive Pyridine Complexes for Electron Transfer Studies and Photoelectrochemical Applications." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6146.
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Sandström, Niclas. "Heavy-Core Staffanes : A Computational Study of Their Fundamental Properties of Interest for Molecular Electronics." Doctoral thesis, Uppsala University, Department of Biochemistry and Organic Chemistry, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7492.
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The basic building blocks in molecular electronics often correspond to conjugated molecules. A compound class consisting of rigid rod-like staffane molecules with the heavier Group 14 elements Si, Ge, Sn and Pb at their bridgehead positions has now been investigated. Herein these oligomers are called heavy-core or Si-, Ge-, Sn- or Pb-core staffanes. These compounds benefit from interaction through their bicyclo[1.1.1]pentane monomer units. Quantum chemical calculations were performed to probe their geometries, stabilities and electronic properties associated with conjugation.
The stabilities of the bicyclo[n.n.n]alkane and [n.n.n]propellanes (1 ≤ n ≤ 3) with C, Si, Ge and Sn at the bridgehead positions were studied by calculation of homodesmotic ring strain energies. The bicyclic compounds with n = 1 and Si, Ge or Sn at bridgehead positions have lower strain than the all-carbon compound.
A gradually higher polarizability exaltation is found as the bridgehead element is changed from C to Si, Ge, Sn or Pb. The ratio between longitudinal and average polarizability also increases gradually as Group 14 is descended, consistent with enhanced conjugation in the heavier oligomers.
The localization of polarons in C-, Si- and Sn-core staffane radical cations was calculated along with internal reorganization energies. The polaron is less localized in Si- and Sn-core than in C-core staffane radical cation. The reorganization energies are also lower for the heavier staffanes, facilitating hole mobility when compared to the C-core staffanes.
The effect of the bicyclic structure on the low valence excitations in the UV-spectra of compounds with two connected disilyl segments was also investigated. MS-CASPT2 calculations of 1,4-disilyl- and 1,4-bis(trimethylsilyl)-1,4-disilabicyclo[2.2.1]heptanes and 1,4-disilyl- and 1,4-bis(trimethylsilyl)-1,4-disilabicyclo[2.1.1]hexanes revealed that although the bicyclic cage separates the two disilyl chromophores, there is a strong red-shift of the lowest valence excitations when compared to an isolated disilane.
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Al-Karkhi, A. "Task recovery in self-organised multi-agent systems for distributed domains." Thesis, University of Essex, 2018. http://repository.essex.ac.uk/22816/.
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Grid computing and cloud systems are distributed systems which provide substantial widely-accessible services to resources. Quality of service is affected by the issues around resource allocation, sharing, task execution and node failure. The focus of this research is on task execution in distributed environments and the effects of node failure on service provision. Most methods in the literature which provide fault tolerance, use reactive techniques; these provide solutions to failure only after its occurrence. In contrast, this research argues that using multi-agent systems with self-organising capabilities can provide a proactive methodology which can improve task execution in open, dynamic and distributed environments. We have modelled a system of autonomous agents with heterogeneous resources and proposed a new delegation protocol for executing tasks within their time constraints. This helps avoid the loss of tasks and to improve efficiency. However, this method on its own is not sufficient in terms of task execution throughput, especially in the presence of agent failure. Hence, we propose, a self-organisation technique. This is represented in this research by two different mechanisms for creating organisations of agents with a certain structure; we suggest, in addition, the adoption of task delegation within the organisations. Adding an organisation structure with agent roles to the network enables smoother performance, increases task execution throughput and copes with agent failures. In addition, we study the failure problem as it manifests within the organisations and we suggest an improvement to the organisation structure which involves the use of another protocol and adding a new role. An exploratory study of dynamic, heterogeneous organisations of agents has also been conducted to understand the formation of organisations in a dynamic environment where agents may fail and new agents may join organisations. These conditions mean that new organisations may evolve and existing organisations may change.
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Steen, Robert. "The Synthesis of Molecular Switches Based Upon Ru(II) Polypyridyl Architecture for Electronic Applications." Licentiate thesis, Västerås : Department of Biology and Chemical Engineering, Mälardalen University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-356.
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Balasuriya, Sumitha. "A computational model of space-variant vision based on a self-organised artificial retina tessellation." Thesis, University of Glasgow, 2006. http://theses.gla.ac.uk/4934/.
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Lei, Chu San. "Systems organised as networks : representation and problem solving with evolutionary computation." Thesis, University of Macau, 1997. http://umaclib3.umac.mo/record=b1445381.
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Grandin, Anna. "Synthetic Routes towards 2-thia-7,8-diaza-cyclopenta[l]phenanthrene and 1-thia-7,8-diaza-cyclopenta[l]phenanthrene for Molecular Electronics Applications." Thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-7505.
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Electric current is known to flow through the π-bonds in oligothiophenes. In order to use them as molecular wires it is important to use a technique where the potential gradients can be generated and maintained in supramolecular networks. A solution to this problem can be the use of metal complexes as junction points within such a network. In this project pathways to synthesize 2-thia-7,8-diaza-cyclopenta[l]phenanthrene (1) and 1-thia-7,8-diaza-cyclopenta[l]phenanthrene (2) for use in molecular electronic devices have been investigated. 4-(5-Bromo-thiophen-2-yl)2,2’-bipyridine (3) was prepared via Kröhnke reaction from 3-(5-bromothiophene-2-yl)acrolein and 1-(2-Oxo-2-pyridine-2-yl-ethyl)-pyridinium iodide in an overall yield of 14 %. Several routes towards 2-thia-7,8-diaza-cyclopenta[l]phenanthrene (1) and 1-thia-7,8-diaza-cyclopenta[l]phenanthrene (2) were tested. Since the original planned pathway did not work, lack of time made it impossible to complete the series of experiments that were needed. The synthesis of 2-thia-7,8-diaza-cyclopenta[l]phenanthrene (1) is almost finished. Due to the solvation problems, after the decarboxylation step, the product could not be analyzed by 1H-NMR in a satisfactory manner. The product was sent for analysis. A number of experiments towards 1-thia-7,8-diaza-cyclopenta[l]phenanthrene (2) were tested but few of them worked as planned. There is a lot of work left to be done in the synthesis of this compound but the lack of time made it impossible. The chemistry that has been achieved is the synthesis of 1,10-phenanthroline-5,6-dione in the synthesis of 2-thia-7,8-diaza-cyclopenta[l]phenanthrene (1). The following Hinsberg thiophene synthesis probably worked but due to solvation problems the product could not be isolated. The final product after hydrolysis and decarboxylation of the remaining ester groups after the Hinsberg thiophene synthesis was tested but the results were difficult to confirm. In the synthesis of 1-thia-7,8-diaza-cyclopenta[l]phenanthrene (2) several attempts to make 3,4-diamino-N,N-diethyl-benzamide were made. The attack from the primary amines on the carbonyl carbon made it necessary to protect them. The attempt to synthesize 3,4-bis-acetylamino-N,N-diethyl-benzamide also failed, both the attempt directly from the carboxylic acid and through the acylchloride, even though the amines were protected.
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Johnev, Boyan. "Chemical engineering of the electronic properties of ITO-organics interface in phthalocyanine-C60-fullerene organic solar cells." [S.l.] : [s.n.], 2006. http://www.diss.fu-berlin.de/2006/104/index.html.
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Ashall, Daniel. "Organic electronic devices : advanced patterning and fabrication approaches." Thesis, Bangor University, 2013. https://research.bangor.ac.uk/portal/en/theses/organic-electronic-devices--advanced-patterning-and-fabrication-approaches(e1fa3b8a-ad6a-4f52-b819-be268244d7c0).html.
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Weston, Laura. "Computational characterisation of organic molecules for electronic applications and an experimental study of cocrystals for electronic devices." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/computational-characterisation-of-organic-molecules-for-electronic-applications-and-an-experimental-study-of-cocrystals-for-electronic-devices(0d1a24ea-3241-40cf-bafa-6be179ba4c26).html.
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A range of small molecules of interest for use in organic semiconductor devices were studied computationally. Trends in geometry, absorption spectra, molecular orbitals, electrostatic potentials, reorganisation energies were studied. Results suggest that, as with acenes, the performance of non-linear cata-condensed polyaromatic hydrocarbons improves as number of fused benzene rings increases. The torsion in these molecules did not appear to have a large impact on the conjugation across the core and little effect on the absorption spectra, although it did affect the reorganisation energies on which charge mobilities depend. Computational studies of mobilities of anthradithiophene molecules were broadly able to reproduce trends seen experimentally and emphasised the importance of crystal morphology. Experimental work was also carried out to search for cocrystals between anthradithiophene derivatives. Many examples were found with some mixtures forming different cocrystals at different mixture ratios. These results were rationalised by a computational study that showed molecules which had a similar binding energy were more likely to be able to form cocrystals. Cocrystal devices were fabricated and 3 out of 7 showed a larger mobility than devices made out of its constituent materials alone. The best of these had a mobility 65% higher than a device made out of the constituent material with the largest mobility. An energy decomposition analysis was carried out on a novel thallophilic system, a complex of thallium with a neutral β-triketimine ligand which was found to form dimers with close Tl-Tl interactions. Calculations show the electrostatic interaction to be repulsive for the dimer with no counter ions, but attractive when 3,5-bistrifluoromethylphenyl borate counter ions are included. This suggests the metallophilic interaction is counter ion-mediated, requiring the anions to provide favourable electrostatics, even in the case of spatially diffuse and distant counter ions such used here. To enable the studies described here software was written for simulating absorption spectra. An implementation into the Gaussian Suite of programs of an energy decomposition scheme and its extension to include an empirical dispersion correction was also carried out.
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Xu, Yunhua. "Synthesis and Photoinduced Electron Transfer of Donor-Sensitizer-Acceptor Systems." Doctoral thesis, Stockholm : Department of Organic Chemistry, Stockholm University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-411.
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Truesdale, Stephen G. "Characterization of the effluent from an intensive marine recirculating system for the culture of fin fish, and studies on effluent based culture of microalgae /." Electronic version (Microsoft Word), 2006. http://dl.uncw.edu/etd/2006/truesdales/stephentruesdale.html.
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Alaskar, Haya Mohmmad. "Dynamic self-organised neural network inspired by the immune algorithm for financial time series prediction and medical data classification." Thesis, Liverpool John Moores University, 2014. http://researchonline.ljmu.ac.uk/4562/.
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Artificial neural networks have been proposed as useful tools in time series analysis in a variety of applications. They are capable of providing good solutions for a variety of problems, including classification and prediction. However, for time series analysis, it must be taken into account that the variables of data are related to the time dimension and are highly correlated. The main aim of this research work is to investigate and develop efficient dynamic neural networks in order to deal with data analysis issues. This research work proposes a novel dynamic self-organised multilayer neural network based on the immune algorithm for financial time series prediction and biomedical signal classification, combining the properties of both recurrent and self-organised neural networks. The first case study that has been addressed in this thesis is prediction of financial time series. The financial time series signal is in the form of historical prices of different companies. The future prediction of price in financial time series enables businesses to make profits by predicting or simply guessing these prices based on some historical data. However, the financial time series signal exhibits a highly random behaviour, which is non-stationary and nonlinear in nature. Therefore, the prediction of this type of time series is very challenging. In this thesis, a number of experiments have been simulated to evaluate the ability of the designed recurrent neural network to forecast the future value of financial time series. The resulting forecast made by the proposed network shows substantial profits on financial historical signals when compared to the self-organised hidden layer inspired by immune algorithm and multilayer perceptron neural networks. These results suggest that the proposed dynamic neural networks has a better ability to capture the chaotic movement in financial signals. The second case that has been addressed in this thesis is for predicting preterm birth and diagnosing preterm labour. One of the most challenging tasks currently facing the healthcare community is the identification of preterm labour, which has important significances for both healthcare and the economy. Premature birth occurs when the baby is born before completion of the 37-week gestation period. Incomplete understanding of the physiology of the uterus and parturition means that premature labour prediction is a difficult task. The early prediction of preterm births could help to improve prevention, through appropriate medical and lifestyle interventions. One promising method is the use of Electrohysterography. This method records the uterine electrical activity during pregnancy. In this thesis, the proposed dynamic neural network has been used for classifying between term and preterm labour using uterine signals. The results indicated that the proposed network generated improved classification accuracy in comparison to the benchmarked neural network architectures.
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Schmitz-Hübsch, Thomas. "Von der organischen Heteroepitaxie zu organisch-organischen Heterostrukturen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2003. http://nbn-resolving.de/urn:nbn:de:swb:14-1070465405156-18243.
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In der vorliegenden Arbeit wurde das Wachstum der planaren aromatischen Moleküle Perylen-3,4,9,10-tetracarbonsäure-3,4,9,10-dianhydrid (PTCDA) und Peri-Hexabenzocoronen (HBC) auf verschiedenen einkristallinen Oberflächen von Gold und Graphit untersucht. Zur Abscheidung der Moleküle und zur Herstellung dünner hochgeordnerter organischer Schichten wurde eine Molekularstrahlepitaxieanlage mit mehreren Kammern aufgebaut. Bei den Untersuchungen des Wachstums von PTCDA auf der Au(111)- und Au(100)-Fläche wurden drei Klassen von Strukturen gefunden: Eine Fischgrätenstruktur, deren Gitterparameter und molekulare Anordnung der (102)-Ebene des PTCDA-Kristalls entsprechen, eine quadratische Struktur, sowie eine Stabstruktur, die der (010)-Ebene des PTCDA-Kristalls zugeordnet werden kann. Während die Stabstruktur auf Au(100) ein inkommensurables Wachstum zeigt, konnten alle anderen PTCDA-Strukturen sowohl auf Au(111) als auch auf Au(100) als point-on-line epitaktisch klassifiziert werden. Die HBC-Schichten auf Au(111), Au(100)hex und Graphit zeigen abweichend von der Kristallstruktur eine hexagonale Symmetrie. Auf Graphit wächst HBC in einer kommensurablen Struktur. Auf den beiden Au-Oberflächen existieren mehrere Strukturen, die sich in ihrer Orientierung und ihren Gitterkonstanten unterscheiden. Neben einer dominierenden HBC-Struktur lassen sich auf den Au-Flächen weitere Strukturen beobachten, deren Auftreten durch den Bedeckungsgrad und die Substratmorphologie, d.h. die Stufenzahl und Terrassengröße des Substrates bestimmt wird. Alle diese HBC-Strukturen konnten als kommensurabel klassifiziert werden. Die Anordnung der HBC-Moleküle in Multilagen wurde für das System HBC auf Au(100)hex mit Hilfe molekularmechanischer Berechnungen modelliert. Die HBC-Moleküle sind in der zweiten Lage gegenüber denen der ersten Lage so verschoben, dass die C-Atome der Moleküle eine graphitähnliche Anordnung zeigen. Wie die STM Untersuchung der organischen Heteroschichten aus HBC und PTCDA zeigen, ist es möglich, epitaktische organische Heteroschichten auch von Molekülen herzustellen, die sich in ihren Gitterkonstanten und in der Symmetrie unterscheiden. Erstmals ließen sich derartige Schichten mittels Rastertunnelmikroskopie direkt und durch LEED auch im reziproken Raum abbilden. Aus dem in den STM Bildern sichtbaren Moirékontrast wurde die Orientierung der beiden organischen Gitter bestimmt. PTCDA wächst bezüglich des HBC-Gitters weder kommensurabel noch point-on-line koinzident, zeigt jedoch eine feste Winkelorientierung. Es handelt sich in diesem Fall um eine inkommensurable Struktur bezüglich des HBC-Gitters, die jedoch bezüglich des zugrundeliegenden Graphitgitters point-on-line Koinzidenz zeigt. Das Versagen der einfachen geometrischen Epitaxiemodelle kann in diesem Fall auf die Existenz mehrerer, energetisch nahezu gleichwertiger Adsorptionsplätze innerhalb der Einheitszelle des Substrates zurückgeführt werden.
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Burghart, Rice Heike S. "Music for Organ and Electronics: Repertory, Notation, and Performance Practice." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1428047354.
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Utas, Josefin. "Hydrogen Bonded Phenols as Models for Redox-Active Tyrosines in Enzymes." Doctoral thesis, Stockholm : Department of Organic Chemistry, Stockholm University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1024.
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Tapper, Markus. "Modell för kombinerad styr- och mätutrustning." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8076.
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Den här högskoleavhandlingen beskriver framtagningen av en modell för en kombinerad styr- och mätutrustning. Syftet med utrustningen är att använda denna för att underlätta vidare utveckling av organisk elektronik vilket är ett av Acreo AB:s forskningsområden. Istället för att till varje ny komponent eller system utveckla ett nytt testsystem kan denna modell användas på ett generellt sätt, vilket sparar värdefull utvecklingstid. I avhandlingen presenteras först de krav som utrustningen ska uppfylla följt av några förslag på lösningar. Därefter väljs ett av förslagen och en grundläggande implementering genomförs med hänsyn mot kraven. Slutligen innehåller rapporten förslag på hur vidare arbete med modellen kan ske.
This bachelor thesis describes the developing of a model for combined steering and measuring equipment. The purpose is to ease further developing of organic electronics, which is one of Acreo AB’s research areas. A test system is needed for every new component or system developed. Instead of constructing a new test environment for every case this equipment will be a general solution that will save valuable developing time. This thesis will first present the requirements followed by some proposal solutions. Thereafter one proposal will be chosen and an essential implementation will be done with consideration of the requirements. Finally the thesis contains suggestions on how to further develop the model.
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Al, Kadi Jazairli Mohamad. "Growth of Zinc Oxide Nanoparticles on Top of Polymers and Organic Small Molecules as a Transparent Cathode in Tandem Photovoltaic Device." Thesis, Linköping University, Department of Science and Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11391.
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Organic solar cells have caught considerable attention in the past few years due to their potential for providing environmentally safe, flexible, lightweight, inexpensive, and roll-to-roll feasible production solar cells. However, the efficiency achieved in current organic solar cells is quite low, yet quick and successive improvements render it as a promising alternative. A hopeful approach to improve the efficiency is by exploiting the tandem concept which consists of stacking two or more organic solar cells in series.
One important constituent in tandem solar cells is the middle electrode layer which is transparent and functions as a cathode for the first cell and an anode for the second cell. Most studies done so far have employed noble metals such as gold or silver as the middle electrode layer; however, they suffered from several shortcomings especially with respect to reproducibility.
This thesis focuses on studying a new trend which employs an oxide material based on nano-particles as a transparent cathode (such as Zinc-oxide-nano-particles) along with a transparent anode so as to replace the middle electrode.
Thus, this work presents a study on solution processable zinc oxide (ZnO) nanostructures, their proper handling techniques, and their potential as a middle electrode material in Tandem solar cells in many different configurations involving both polymer and small molecule materials. Moreover, the ZnO-np potential as a candidate for acceptor material is also investigated.
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Anderson, Matthew A. (Matthew Alexander). "Frequency distributions of Escherichia coli subtypes in various fecal sources over time and geographical space [electronic resource] : application to bacterial source tracking methods / by Matthew A. Anderson." University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000206.
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Thesis (M.S.)--University of South Florida, 2003.
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ABSTRACT: Bacterial source tracking (BST) methods often involve the use of phenotypic or genotypic fingerprinting techniques to compare indicator bacteria such as Escherichia coli isolated from unknown sources against a library of fingerprints from indicator bacteria found in the feces of various known source animals. The predictive capability of a library is based in part on how well the library isolates reflect the true population diversity of indicator bacteria that can potentially impact a water body. The purpose of this study was to compare the behavior of E. coli population structures in the feces of humans, beef cattle and horses across different parameters. Ribotyping and antibiotic resistance analysis were used to "fingerprint", or subtype E. coli isolates. Significantly greater diversity was observed in the E. coli population of horses compared to the human or beef cattle sampled.
ABSTRACT: Subtype sharing between individuals from all host categories was infrequent, therefore the majority of E. coli subtypes were sampled from a single individual. The dominant E. coli populations of nine individuals (three per host source category) were monitored over time, which demonstrated that E. coli subtypes within a host individual vary on a monthly time frame, and an increase in the frequency of subtype sharing was noted between individuals within the same source group over time. The E. coli population of a single human that had just finished antibiotic treatment was studied on a daily basis for one month. The loss of an E. coli subtype with high antibiotic resistance was observed over time, however there was a single dominant E. coli subtype that was present at every sampling event during the entire month. Geographic distinctiveness of E. coli populations was investigated by sampling four herds located in different geographical regions. We observed that E.
ABSTRACT: coli populations are not geographically distinct, but are somewhat individual-specific, as most E. coli isolates had a subtype that was found in a single individual. This study defines factors that should be considered when constructing a successful BST library, and suggests that E. coli may not be the appropriate indicator organism for BST.
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Sayegh, Adnan. "Dérivation des électrons photosynthétiques par des quinones sur organisme entier : le cas de Chlamydomonas reinhardtii." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS098.
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L'énergie est un enjeu crucial pour les sociétés actuelles et le recours à des énergies alternatives est de jour. Or la photosynthèse apparaît comme une piste intéressante et les unités photosynthétiques comme des convertisseurs potentiels sélectionnés par l'Evolution. Lors de la photosynthèse électron poursuit son cheminement le long de la chaîne photosynthétique pour permettre la mise en marche des différents complexes enzymatiques nécessaires au maintien en vie de l'organisme photosynthétique. L'étape cinétiquement limitante de ce transfert électronique se situe en amont du cytochrome b6f. C'est cette limitation qui serait responsable des dommages encourus par les algues sous forte lumière connus sous le nom de photoinhibition. Ainsi pour ne pas compromettre la vie de l'algue unicellulaire Chlamydomonas reinhardtii, la stratégie mise en place durant ces travaux de thèse a été de dériver les électrons d'une manière sélective en amont de l'étape cinétiquement limitante. Pour cela des quinones exogènes ont été utilisées comme accepteurs d'électrons capables d'atteindre la chaîne photosynthétique, de récupérer les électrons et de venir s'oxyder à l'électrode polarisée. Une demi-pile a été mise en place et la stabilité du courant dans le temps étudiée. Une toxicité des quinones a en particulier été mise en évidence et serait responsable de la dégradation des performances du système au cours du temps. Les spectroscopies de fluorescence et d'absorption ont pu fournir des éléments de réponse. Des critères de choix de quinones ont été identifiés et partant de là, de la synthèse organique a été effectuée pour essayer de trouver un compromis entre dérivation et toxicitéPhotosynthetic electron derivation on living organism using quinones : the case of Chlamydomonas reinhardtii Nowadays, energy is a major concern to societies and research is focusing on finding new sources of clean and sustainable energy. In this context, photosynthesis may be an appropriate way to meet this objective. Indeed solar light provides the chemical energy required by photosynthetic organisms to maintain their cellular activity. Taking advantage of photosynthesis to produce a photocurrent requires intercepting electrons exchanged in the oxidation/reduction processes occurring along the photosynthetic chain. This is why we consider here an electrochemical device involving a gold electrode able to derivate photosynthetic electrons from a population of Chlamydomonas reinhardtii algae. However photosynthsesis is a multi-speed process and a rate controlling step was identified just before the b6f complex. This is why the strategy of this work aimed at deriving electrons before the b6f cytochrom. This allows to relieve algae from stress under high light conditions. Known as efficient PSII acceptors, quinones were used as exogenous mediators to transfer the electrons from the photosynthetic chain to the electrode surface. Therefore, the resulting photocurrents under illumination, were commented and discussed in order to understand and define the best appropriate experimental conditions for this bio-solar generator. Quinones were shown to induce toxicity on algae. Focus was directed on finding the best chemical structure which would combine good derivation properties and little toxicity
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Fabuel, Ruiz David. "Sistemas electrónicos para la caracterización de la conductividad y electroluminiscencia de materiales inorgánicos y poliméricos. Modelado de dispositivos OLEDs precomerciales." Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/8961.
Full textAbstract:
La presente tesis doctoral va encaminada a avanzar en el conocimiento de dispositivos electroluminiscentes. La tesis consta de dos partes diferenciadas.
La primera de ellas ha sido dirigida al diseño y construcción de equipos electrónicos que permitan la caracterización eléctrica y la medida de emisión de luz en dispositivos electroluminiscentes constituidos por nuevos materiales híbridos orgánicos-inorgánicos particulados de baja eficiencia de emisión. En concreto en esta primera parte de la tesis se ha construido un sistema de caracterización eléctrica que permite obtener medidas de pastillas de materiales particulados a presión, Tª y grado de humedad determinadas. Además se ha procedido a la modificación de un equipo de fluorescencia comercial para adaptarlo a medidas de películas electroluminiscentes de eficiencia inferior a 1cd/m2. Con los equipos realizados se ha procedido a la caracterización eléctrica y luminiscente de una serie de materiales híbridos particulados con el fin de entender los mecanismos de conducción de estos sistemas supramoleculares.
La segunda parte de la tesis ha ido dirigida a desarrollar un modelo basado en el software de simulación SPICE que permita simular la característica de Luminosidad (L), Corriente (I), Voltaje(V) y Temperatura (Tª) de paneles OLEDs preinsdustriales de gran área enfocados a iluminación general. En la tesis se describen también los procedimientos y medidas para conseguir los valores de los parámetros de entrada a estos modelos. Con estos parámetros de entrada se simularon varios paneles preindustriales de OLEDs y se compararon con la caracterización de paneles reales con el fin de validar el modelo. A continuación se procedió a la realización de simulaciones de tipo predictivo que permitiesen mejorar la homogeneidad luminosa de este tipo de paneles al variar determinados parámetros constructivos de estos comprobándose que es posible eliminar prácticamente los efectos de la inhomogeneidad luminosa.Fabuel Ruiz, D. (2010). Sistemas electrónicos para la caracterización de la conductividad y electroluminiscencia de materiales inorgánicos y poliméricos. Modelado de dispositivos OLEDs precomerciales [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8961
Palancia
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Baptista, Filipa Alexandra Lourenço. "Evaluation of the applicability of an electronic device in counting and chromatic differentiation in ecotoxicology assays." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22686.
Full textAbstract:
Mestrado em Biologia AplicadaO presente estudo foi realizado no âmbito da Biologia Aplicada tendo como objetivo geral a avaliação da aplicabilidade de um novo dispositivo (D counter) em ensaios biológicos no âmbito da Ecotoxicologia. O trabalho desenvolvido apresentou três fases distintas: uma fase inicial com adaptação aos comandos e funcionalidades do novo equipamento, uma segunda fase com aplicação da metodologia clássica em paralelo com a abordagem otimizada pelo equipamento D counter, e uma terceira fase com a execução de um teste ecotoxicológico, usando unicamente as potencialidades oferecidas pelo D counter, focando-se principalmente na contagem de caracterização cromática de organismos. Avaliações preliminares acerca da aplicabilidade do D counter em contar e diferenciar cromaticamente microrganismos, em testes ecotoxicológicos, foram apresentadas na SETAC2017 (Bruxelas). O resumo estendido encontra-se no capitulo II, onde estão descritas as principais funcionalidades do D counter, cujo objetivo se foca na simplificação e automatização dos testes ecotoxicológicos, por forma a minimizar problemas inerentes ao método clássico de contagem e caracterização de organismos. Grande parte dos testes com Daphnia magna requerem a contagem e medição de elevado número de organismos, o que pode causar erros humanos e prejudicar a acuidade visual do técnico. Desta forma o procedimento de trabalho com o D counter acrescenta objetividade e precisão, economizando tempo e diminuindo o tempo de exposição ao químico testado. A segunda fase do estudo pretendeu avaliar o D counter em estudos biológicos clássicos. Para tal, comparou-se a performance deste com a abordagem tradicional, através de um ensaio crónico de 21 dias com D. magna, por forma a avaliar parâmetros como a reprodução e o crescimento dos organismos, usando os dois métodos, na ausência de contaminante. Numa terceira fase aplicou-se a nova metodologia a um teste crónico, onde foram estudados os efeitos combinados da variação da dureza da água e amónia em D. magna. Os parâmetros estudados foram a reprodução e o crescimento dos organismos, com base nos resultados obtidos no D counter. De uma forma global, este estudo demonstrou que o novo equipamento não exibe diferenças significativas em comparação com o método clássico (p = 0,822), mostrando-se assim capaz de substituir a metodologia atualmente utilizada. Dados do D counter, mostram que a dureza e a amónia demonstraram ser parâmetros que afetam o tamanho e reprodução dos organismos. Meio com valor mais baixo de dureza resulta em organismos com menor tamanho, enquanto o oposto se observou no meio com dureza mais elevada. Contrariamente ao esperado, concentrações mais altas de cloreto de amónia (12 e 20 mg/l) apresentaram maiores taxas de reprodução em comparação com o controlo e concentração mais baixa de cloreto de amónia (2mg/l). Este estudo demonstra e valida a aplicação de novas metodologias na área da ecotoxicologia, podendo abrir novas potencialidades e evoluções do equipamento no futuro. resumo
The present study was developed in the ambit of Applied Biology aiming the evaluation of an innovative device applicability in Ecotoxicology bioassays. The study was developed in three distinct phases: a first phase with adaptation to the commands and functionalities of the new equipment (D counter); a second phase using both classical methodology and the innovative approach (provided by the new device) in bioassays; and a third phase performing a standard bioassay in Ecotoxicology, only assisted by the functionalities available from the D counter, mainly in organism counting and chromatic characterization. Preliminary results evaluating the applicability of D counter in counting and chromatic differentiation in Ecotoxicology bioassays were presented at SETAC2017 (Brussels). The study presented to the conference is included in chapter II as an extended abstract, enhancing D counter main features simplifying and automating ecotoxicological tests, minimizing many problems inherent to the classical method of counting and characterizing organisms. Many Daphnia magna testing requires the counting and measurement of large amounts of organisms, which can lead to human error and even impair the visual acuity of the technician. The working procedure with D counter adds objectiveness and accuracy, saves time, and also reduces the exposure period to the chemical tested. A second phase of the present study was to evaluate D counter in classical bioassays tests, comparing D counter performance and the traditional approach, through an essay with D. magna, considering a chronic test of 21 days, and evaluating parameters such as reproduction and growth of the organisms using both procedures in the absence of contamination. In a third phase, the new methodology was applied to chronic test, where the combined effects of the variation of water hardness and ammonia in D. magna were studied. The studied parameters were reproduction and growth of the organisms exposed to combined effects, considering data only acquired and provided by the new device D counter. Overall, this study demonstrated that the new equipment does not exhibit significant differences, when compared to the classical method (p = 0,822), thus being able to assist or even replace the current counting methodology. D counter data showed that water hardness and ammonia have shown to be parameters that affect the size and reproduction of organisms. Medium with lower hardness results in organisms with smaller size, while the opposite was observed in the medium with higher water hardness. Unexpectedly, higher concentrations of ammonium chloride (12 and 20 mg/l) presented higher reproduction rates, compared to the control and lower concentration of ammonium chloride (2mg/l). This study presents and validates the application of new methodologies in ecotoxicology, being able to open new potentialities and evolutions of the equipment in the future. abstract
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Hamer, Bastiaan. "Performance evaluation and development of contact solutions for flexible organic solar cells." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-19742.
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In today’s society many non-renewable and environmentally harming energy sources are used to facilitate people’s everyday energy demands. This causes ecosystems to break down, global temperatures to rise, pollution and many more critical long lasting problems. By replacing non-renewable energy sources and taking advantage of the 100% renewable energy source, light, these problems will diminish. This project has been in collaboration with a company called Epishine who develop indoor organic solar cell devices to be able to replace conventual battery driven electrical devices with solar power harvested from indoor light. Since there is no good existing contacting solution, for Epishine to be able to enter the market, a contact solution between their solar cell device and the electrical devices it will power has to be developed. This thesis focuses on developing, designing, testing and evaluating the performance of new contact solutions for encapsulated flexible organic printed solar cells with the feasibility, viability, scalability and durability in focus. This project was conducted by first performing a literature study, thereafter, establishing a baseline for future referencing of new contact solutions and the main part, developing new concepts and evaluating them. By using the design thinking method, an iterative process could take place, allowing for a constant flow of new ideas whilst testing concepts throughout the project. The baseline tests were successful and the hypothesis of organic materials degrading over time was confirmed. From the many sub-concepts and production methods for a new contacting solution, two concepts showed promising results and were merged into one main concept. Two devices were created with the new concept, one functional device and one showing the design. To conclude, the thesis resulted in a functional solar cell device with a new contact solution which shows great potential and a new production method which enables all organic printed electronics to be design and developed in a more compact and component dense design. This production method is beneficial to not only Epishine, but everywhere where printed electronics are used and need to be optimized due to restrictions such as space and weight.I dagens samhälle används många icke-förnybara energikällor för att underlätta människans vardagliga behov men skadar samtidigt miljön. Detta leder till att hela ekosystem fallerar, den globala temperaturen stiger, giftiga ämnen släpps fria och flera kritiska, långvariga problem skapas. Genom att byta ut icke-förnybara energikällor och istället dra nytta av den 100 % förnybara energikällan, ljus, kommer dessa ovanstående problem att minska. Detta projekt har varit i samarbete med ett företag vid namn Epishine som utvecklar organiska solcellsenheter för inomhusbruk, för att kunna ersätta konventionella batteridrivna elektriska apparater med solenergi tillvaratagen av inomhusbelysning. I dagsläget finns det ingen bra kontaktlösning mellan solcellsenheten och den apparat den ska driva, vilket är ett av Epishines större problem i nuläget, som hindrar dem från att kunna slå igenom på marknaden. Denna avhandling fokuserar på att utveckla, designa, testa och utvärdera prestandan av nya kontaktlösningar för inkapslade flexibla organiska solceller. Projektet började med en litteraturstudie, därefter etablerades en ”baseline” för att kunna jämföra de nya kontaktlösningarna. Största delen av rapporten handlar om att utveckla och testa nya kontaktlösningar för att sedan utvärdera dem. Genom att använda ”Design thinking” processen, kunde en iterativ process äga rum, vilket möjliggjorde ett konstant flöde med nya idéer som genererades samtidigt som koncept och prototyper utvecklades och utvärderades. Resultaten av ”baseline”-testerna var framgångsrika och hypotesen om att de konduktiva egenskaperna av organiska material försämras med tiden bekräftades. Från alla delkoncept och potentiella produktionsmetoderna för en ny kontaktlösning visade två koncept lovande resultat och slogs därför samman till ett huvudkoncept. Två olika solcellsenheter skapades med den nya kontaktlösningen implementerad. En funktionell enhet skapades och en enhet som visar layouten och designen. Sammanfattningsvis resulterade avhandlingen i en funktionell solcellsenhet med en ny kontaktlösning som visar stor potential samt en ny produktionsmetod som gör att all organisk tryckt elektronik kan designas och tillverkas i en mer kompakt och komponenttät design. Denna produktionsmetod är en fördel inte bara för Epishine utan också överallt där tryckt elektronik används och behöver optimeras i form av utrymme och vikt.
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Durán, Giner Eva de Les Neus. "Fotólisis de N-óxidos heterocíclicos. Caracterización de los estados excitados, reactividad frente a dadores de electrones y generación de oxígeno atómico." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/84286.
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The general aim of the present thesis is to undertake a thorough photochemical study on a family of aromatic N-oxides. Specifically, the selected compounds are 4-desoxytirapazamine (DTPZ) and 4-nitroquinoline N-oxide (NQNO), and the study is focused on their photophysical and photochemical characterization, as well as on the interaction of their excited states with other molecules of interest. Both the singlet and triplet excited states of DTPZ have been spectroscopically characterized. Thus, using laser flash photolysis in the femtosecond time scale the transient absorption spectrum corresponding to 1DTPZ* has been observed. In addition, laser flash photolysis in the nanosecond time scale has allowed us to obtain the transient spectrum corresponding to 3DTPZ*. From the fluorescence and phosphorescence emission spectra, the energies of the singlet and triplet excited states have been estimated. Moreover, in the nano-FDL experiments a negative band has been observed and assigned as "P-TYPE delayed fluorescence" based on the influence of different experimental conditions. As regards NQNO, its singlet excited state of (1NQNO*) has also been characterized by different spectroscopic techniques, combining transient absorption with steady state and time-resolved emission spectroscopy. The energy of 1NQNO* has been established from the fluorescence spectrum, whereas its lifetime in the femto-FDL experiments, where a characteristic S1-Sn absorption band is observed. In a first stage, the triplet excited state of NQNO (3NQNO*) has also been characterized by emission spectroscopy. Thus, from the steady-state phosphorescence spectrum the triplet energy has been estimated. Formation of 3NQNO* by intersystem crossing has been monitored by femto-FDL, giving rise to an isosbestic point. The characterization of 3NQNO* has been completed by nano-LFP, using oxygen as well as ¿-carotene as quenchers. In addition, quenching of 3NQNO* electron donors is also observed in aprotic solvents, leading to the radical anion of NQNO (¿-NQNO). If there is a proton source in the medium, protonation of the radical anion results in formation of the neutral radical of NQNO (¿NQNOH). In general, all processes are slower in protic solvents because of the solvation sphere. Moreover, it has been observed by nano-FDL that 3NQNO* is quenched by tryptophan (Trp) via an electron transfer mechanism. In the presence of human serum albumin protein a similar interaction is observed, pointing to a close proximity between NQNO and the Trp residue of HSA and revealing that the N-oxide is indeed located in inside the protein cavities. The singlet excited state of Trp is also quenched by NQNO, leading to formation of an exciplex that emits at longer wavelength than the non-complexed amino acid. The same process is observed in HSA, providing further evidence in support of the proximity between NQNO and the Trp residue of the protein and NQNO. Thus, it is proven that NQNO enters into the protein and is hosted close to the Trp unit of HSA. Finally, pyridine N-oxide, PDZNO and NQNO have been used to generate atomic oxygen (O(3P)) through photochemical cleavage of the N-O bond. Although it has not been possible to achieve the direct detection of this reactive oxygen species, its generation has been evidenced by nano-LFP, using acetonitrile for chemical trapping. Under these conditions, formation of the nitrilium oxide MeCNO is monitored at 340 nm. Alternatively, using PDZNO as source of O(3P) and benzene as solvent, atomic oxygen is trapped by benzene to give phenol, which can be analyzed by gas chromatography. Following this approach, it has been demonstrated that O(3P) is efficiently scavenged by the solar filter BEMT . Incorporation of oxygen to the UV-filter has been demonstrated and occurs mainly at the methoxylated ring. Therefore, BEMT has a double function, acting both as UV-filter and as antioxidant.Profundizar en el estudio de los N-óxidos es el objetivo de la presente tesis. Así pues, se han seleccionado los compuestos 4-desoxitirapazamina (DTPZ) y 4-nitroquinolina N-óxido (NQNO) para su caracterización fotofísica y fotoquímica y el estudio de las interacciones con diversas moléculas. Se han caracterizado los estados excitados singlete y triplete del compuesto conocido como 4-desoxitirapazamina. Además, por FDL se ha caracterizado las bandas de absorción transitoria S1-Sn y T1-Tn,. También, por espectroscopía de emisión se han caracterizado, las energías de los estados excitados singlete y triplete. Así mismo, se ha descrito una banda adicional observada por nano-FDL y asignada, como fluorescencia retardada de Tipo P. Por otro lado, se ha caracterizado el estado excitado singlete del compuesto 4-nitroquinolina N-óxido por distintas técnicas espectroscópicas de absorción y emisión en estado estacionario y con resolución temporal. Se ha registrado su espectro de fluorescencia y calculado la energía del estado excitado singlete, y por femto-FDL se ha podido caracterizar el espectro de absorción S1-Sn,, así como el tiempo de vida del estado excitado singlete. También, se ha caracterizado el estado excitado triplete de 4-nitroquinolina N-óxido, por espectroscopía de emisión, obteniendo su espectro de fosforescencia y calculando la energía de 3NQNO* y su tiempo de vida. Para completar la caracterización del estado excitado triplete se han utilizado como desactivadores: oxígeno y ¿-caroteno. Siguiendo con la caracterización de NQNO, se ha identificado la reactividad de su estado excitado triplete desde su formación a su desactivación, desencadenando diversos comportamientos según las condiciones. Así se observa que el triplete en presencia de dadores de electrones y en disolvente aprótico da lugar al radical anión tras una transferencia electrónica. Mientras que si en el medio existe un dador de protones, se produce una protonación del radical obteniendo el radical anión protonado de NQNO. Los procesos en disolvente prótico están ralentizados debido a su esfera de solvatación. Por otra parte, se ha observado que el estado excitado triplete de NQNO se desactiva al ser excitado por nano-FDL en presencia de triptófano por un mecanismo de transferencia electrónica, dando lugar al radical protonado de NQNO. En presencia de proteína transportadora albúmina sérica humana se observa una interacción similar, lo que indica que el N-óxido se sitúa dentro de la proteína y mantiene una proximidad espacial con el Trp de la cadena peptídica. Por lo que respecta al estado excitado singlete del Trp, éste se desactiva en presencia de NQNO, dando lugar a la formación de un exciplejo que emite a longitudes de onda mayores a las del singlete del aminoácido. Dicho proceso también ocurre con la albúmina, lo que nos vuelve a indicar que la molécula de NQNO se sitúa dentro de la estructura terciaria de la proteína y próxima a la posición del aminoácido Trp. De forma paralela, se han usado los N-óxidos heterocíclicos PYRNO, PDZNO y NQNO para obtener oxígeno atómico (O(3P)) a partir de la ruptura fotoquímica homolítica del enlace N-O. Aunque no ha sido posible la detección directa de oxígeno atómico, , sí se han desarrollado dos métodos para identificar los productos resultantes de la captura química de O(3P). Así, mediante nano-FDL se ha observado la formación del óxido de acetonitrilo como especie transitoria en las disoluciones de PYRNO, PDZNO y NQNO en acetonitrilo. Por otra parte, a través de la irradiación de PDZNO disuelto en benceno en estado estacionario, se ha detectado la formación de fenol por cromatografía de gases. Además se ha demostrado la gran afinidad del filtro solar bemotrizinol por el oxígeno atómico. También se ha evidenciado la incorporación de oxígeno a la estructura del filtro solar, teniendo lugar la oxidación preferentemente en el sust
Aprofundir a l'estudi dels N-òxids es l'objectiu de la present tesi. Així donç, s'han seleccionat els compostos 4-desoxitirapazamina (DTPZ) y 4-nitroquinolina N-òxid (NQNO) per a la seua caracterització fotofísica i fotoquímica i l'estudi de les interaccions amb diverses molècules. S'han caracteritzat els estats excitats singlet i triplet del compost conegut com a 4-desoxitirapazamina. A més a més, s'han observat per FDL les bandes d'absorció transitòria S1-Sn i T1-Tn. També, s'han caracteritzat les energies dels estat excitats singlet i triplet, així com el temps de vida de fosforescència. Així, s'ha descrit una banda addicional observada com a fluorescència retardada de Tipo P. També, s'ha caracteritzat l'estat excitat singlet del compost 4-nitroquinolina N-òxid per tècniques espectroscòpiques d'absorció y emissió en estat estacionari i amb resolució temporal. S'ha registrat el seu espectre de fluorescència, i per FDL a l'escala ultrarràpida de femtosegons s'ha pogut caracteritzar l'espectre de absorció S1-Sn,, així com el temps de vida. També, s'ha caracteritzat l'estat excitat triplet de 4-nitroquinolina N-òxid, per espectroscopia d'emissió, obtenint el seu espectre de fosforescència y calculant l'energia de 3NQNO* i el seu temps de vida. Per a completar la caracterització del estat excitat triplet s'ha utilitzat desactivadors de l'estat excitat triplet (oxigen y ¿-caroten). Seguint amb la caracterització de NQNO, s'ha identificat la reactivitat del seu estat excitat triplet des de la seua formació (com s'observa a l'isosbèstic per femto-FDL) a la seua desactivació observada per nano-FDL, desencadenant diversos comportaments segons les condicions. Així s'observa que e triplet en presència de donadors d'electrons amb dissolvents apròtics dona lloc al radical anió després d'una transferència electrònica. Mentre que si al medi existeixen donadors de protons, es produeix una protonació del radical i s'obté el radical anió protonat de NQNO. Els processos en dissolvents pròtics està enrederits degut a l'esfera de solvatació. D'altra banda, s'ha observat que l'estat excitat triplet de NQNO es desactiva al ser excitat per nano-FDL en presencia de triptòfan (Trp). Això ocorre per un mecanisme de transferència electrònica, donant lloc al radical protonat de NQNO. En presència de proteïna transportadora albúmina sèrica humana s'observa una interacció similar, el que indica que l' N-òxid es situa dintre de la proteïna i es manté una proximitat espacial amb el Trp de la cadena peptídica. Pel que fa a l'estat excitat singlet de Trp, es desactiva en presencia de NQNO donant lloc a la formació d'un exciplex que emitix a longituds d'ona majors a les del singlet de l'aminoàcid. Aquest procés també ocorre amb la albúmina, el que torna a indicar que la molècula de NQNO es situa dins de la estructura terciària de la proteïna pròxima a la posició del aminoàcid Trp. De forma paral¿lela s'han gastat els N-òxid heterociclics piridina N-òxid (PYRNO), piridazina N-òxid (PDZNO) i NQNO per a obtindre oxigen atòmic (O(3P)) a partir de la ruptura fotoquímica homolítica de l'enllaç N-O. Encara que no ha sigut possible la detecció directa de l'oxigen atòmic, s'han desenvolupat dos mètodes per a identificar els productes resultants de la captura química de O(3P). Així, amb la tècnica espectroscòpica de FDL s'ha observat la formació de l'òxid d'acetonitril com a espècie transitòria a les dissolucions de PYRNO, PDZNO i NQNO en acetonitril. D'altra banda, a través de l'irradació de PDZN dissolt en bencé en estat estacionari s'ha detectat la formació de fenol per cromatografia de gasos. Amés s'ha demostrat la gran afinitat del filtre solar bemotrizinol per l'oxigen atòmic i s'ha evidenciat la incorporació d'oxigen a la estructura del filtre solar a través, produint-se l'oxidació preferentment al substituent metoxilat. Per tant, bemotrizimol utilitzat general
Durán Giner, EDLN. (2017). Fotólisis de N-óxidos heterocíclicos. Caracterización de los estados excitados, reactividad frente a dadores de electrones y generación de oxígeno atómico [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84286
TESIS
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Juwana, Sri. "Aquaculture of Carcinus maenas L. (Decapoda: Portunidae) with emphasis on colonizations of the surface of the larvae by micro-organisms : a scanning electron microscopy study." Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264770.
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Parfitt, Geraint. "Proteoglycans as dynamic regulators of the organised collagen fibril architecture in the cornea : an electron tomography study of the mouse corneal stroma." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/55104/.
Full textAbstract:
The cornea is the primary refractive element of the eye and is also fundamental to the protection of the visual system. Collagen is the major constituent of the cornea, where it is organised in a lattice that enables corneal transparency. Proteoglycan macromolecules are thought to regulate the diameter and spatial order of collagen fibrils in the cornea, which are both pre-requisites for corneal transparency, although the mechanisms by which they organise fibrils are not fully elucidated. This investigation examined the morphology, morphometry and organisation of proteoglycans three-dimensionally, in both normal and genetically altered mouse corneas, to gain a greater understanding of proteoglycan structure-function relationships. In summary, we found that proteoglycans are primarily responsible for the remarkable collagen organisation in the mouse cornea, which allows for corneal transparency. The self- association of proteoglycans into complexes is likely to result in a robust attachment of neighbouring fibrils and provides biomechanical strength, whilst sulphation patterns are seen to have a direct effect on the aggregation potential of proteoglycans. Removal of proteoglycans, particularly lumican, affects the regulation of both fibril size and spatial order, both required for corneal transparency.
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Fouilland, Laura. "Synthesis of novel 1.10-phenanthrolins and cyclic analogs, a potential anticancer and antimalarial agents." Thesis, KTH, Skolan för kemivetenskap (CHE), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32945.
Full textAbstract:
The potential antimalarial and anticancer effect of molecules containing 1,10-phenanthroline skeleton has been suspected on several previous studies. It is why the goal of this project is to synthesize novel 1,10-phenanthrolines and cyclic analogs. The originality of this project is the synthesis way of these novel compounds. Indeed, these structures will be obtained through an original redox approach developed in the SMITH laboratory using the tetrakis(dimethylamino)ethylene (TDAE) reagent. The TDAE is an electron rich organic molecule which is an effective reducing agent capable of generating an anion from halogenated derivatives under mild conditions via a single electron transfer (SET). From the different substrate we will work with, the TDAE will generate an anion which will be additioned on the 1,10-phenanthroline-5,6-dione. These different substrates will be aromatic and heterocyclic nitro-benzylic, and quinonic derivates as well as bromodifluoromethyl heteroarylated substrates. A one pot two step (reduction, dehydration) reaction will be done on these addition products, in order to obtain a cyclised product. It is the first time we try these reactions on these kind on molecules, it is why this project needs a lot of optimization and that the yield obtained are medium or equal to zero. However, we observed that the addition reaction with TDAE worked with 4 substrates out of 6. We tried the cyclisation reaction on only one addition product and we think that after some improvement of the reaction conditions and the work-up, we will be able to obtain the product with a good yield.Tidigare studier har indikerat att molekyler med 1,10-phenanthrolineskelett har en skyddande effekt mot malaria och cancer. Syftet med detta projekt är att syntetisera nya 1,10-phenanthrolinar och cykliska analoger. Framställningsmetoden som användes i denna studie har inte undersökts tidigare. Föreningen skapades genom en originalmetod utnyttjande en redoxreaktion med hjälp av en TDAE-reagens. TDAE är en elektronrik organisk molekyl och fungerar som en effektiv reduktionsagent. Med hjälp av en enelektronöverföring (SET) kan en anjon framställas under milda förhållanden utifrån halogena derivat. Anjonen tillförs 1,10-phenanthroline-5,6-dione. De olika substraten är heteroaromatiska nitro-benzyliska och quinoniska derivat, samt bromodifluorometylheteroarylerade. Cykliska produkter erhölls genom en tvåstegsreaktion (reduktion, dehydratisering) genomförd i ett enda reaktionskärl. Med detta projekt har dessa reaktioner för första gången testats på den här typen av molekyler. Det krävs mer optimering eftersom utbytena var låga till medelhöga. Utav sex möjliga substrat fungerade additionsreaktionen med TDAE med fyra stycken. I detta försök testades dock endast en cyklisk reaktion på additionsprodukten. Med ytterligare förbättringar av reaktionsvillkor och upparbetningar förväntas man kunna producera önskad produkt i gott utbyte.
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Tibbelin, Julius. "Organic Heavy Group 14 Element Compounds : A Study of Their Chemical Bonding Properties Directed Towards Applications as Molecular Wires and in Synthesis." Doctoral thesis, Uppsala universitet, Institutionen för biokemi och organisk kemi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-123088.
Full textAbstract:
The research described herein includes synthesis, spectroscopy, and quantum chemical calculations with focus on the characteristic properties of compounds with bonds between carbon and the heavier Group 14 elements. The chapters based on the first four papers concern σ- and σ/π-conjugated compounds, although the focus of the first paper is on ring strain of bicyclo[1.1.1]pentanes with C, Si, Ge or Sn at the bridgeheads. The relationship between calculated homodesmotic ring strain energies and through-space distances between the bridgehead atoms was evaluated, and it was found that replacing one of the methylene bridges with phospha-methyl gave both low strain and short through-space distance. Two kinds of σ/π-interacting systems were analysed with the difference that the σ- and π-bonded segments were either allowed to rotate freely relative each other or frozen into a conformer with maximal σ/π-interaction. The freely rotating systems are star-shaped oligothiophenes linked by heavy alkane segments. Density functional theory (DFT) calculations of hole reorganization energies support the measured hole mobilites. In summary, longer central oligosilane linkages, when compared to shorter, facilitate intermolecular hole-transfer between oligothiophene units. In 1,4-disilacyclohexa-2,5-dienes, the strength of the π- and pseudo-π interaction depends on the substituents at Si. Vapour phase UV absorption spectroscopy of 2,3,5,6-tetraethyl-1,1,4,4-tetrakis(trimethylsilyl)-1,4-disilacyclohexa-2,5-diene reveals a strong absorption at 273 nm (4.50 eV). Time-dependent DFT calculations further indicate that octastannylated 1,4-disilacyclohexa-2,5-diene has is lowest excited state at 384 nm (3.23 eV). The electronic, geometric and optical properties of substituted 1,4-disilacyclohexa-2,5-dienes were compared with those of the correspondingly substituted siloles. It was found that the lowest excitations of siloles are less tunable than those of 1,4-disilacyclohexa-2,5-dienes. The final section concerns strongly reverse-polarised 2-amino-2-siloxysilenes formed thermally from carbamylpolysilanes, and their lack of reaction with alcohols. Instead, the carbamylsilane reacts with alcohols giving silyl ethers, leading to a new benign route for alcohol protection.
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Garcia, Virgile. "Optimisation du partage de ressources pour les réseaux cellulaires auto-organisés." Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00838793.
Full textAbstract:
Cette thèse s'intéresse aux problèmes d'allocations des ressources et de puissance dans les réseaux cellulaires de quatrième génération (4G). Pour faire face à la demande continuellement croissante en débit des utilisateurs mobiles, les opérateurs n'ont d'autre choix que de densifier leurs infrastructures d'accès au réseau radio (RAN), afin de maximiser l'utilisation de la bande passante disponible dans l'espace. Un des défis de cette nouvelle architecture est la coexistence de nombreuses cellules voisines et la gestion des interférences co-canal qu'elles génèrent entre elles. De telles contraintes ont amené la communauté scientifique à s'intéresser aux réseaux auto-organisés et auto-optimisés (SON), qui permettent aux réseaux de s'optimiser localement via des décisions décentralisées (sans planification statique). L'intérêt principal de tels réseaux est le passage à l'échelle des algorithmes distribués et la possibilité de s'adapter dynamiquement à de nouveaux environnements. Dans cette optique, nous proposons l'étude de deux problèmes d'allocation de ressources. La première partie de cette thèse se concentre sur l'optimisation de l'usage des ressources, dans un contexte de transmission coordonnée par plusieurs stations de base (CoMP). Les performances de la coordination de stations de base sont évaluées, selon le critère de capacité uniforme, ainsi que le compromis entre l'efficacité spectrale et l'équité entre les utilisateurs. Nous proposons également une méthode généralisée et distribuée de sélection de l'ensemble de stations en coopération, afin d'optimiser le compromis efficacité-équité. Dans une seconde partie, nous nous intéressons à l'optimisation de l'allocation des ressources et de puissance, dans le but de minimiser la consommation électrique du réseau. Nous présentons deux algorithmes dont les décisions sont décentralisées. Le premier est basé sur une optimisation stochastique (via l'échantillonneur de Gibbs) et permet une optimisation globale du système. Le second quant à lui est basé sur l'adaptation de la théorie du contrôle et utilise des modèles prédictifs et la poursuite de cibles pour allouer les ressources et les puissances dans un contexte de canaux et d'interférences dynamiques. Dans de nombreux cas, plusieurs objectifs concurrents sont à considérer pour évaluer les performances d'un réseau (capacité totale, équité, consommation électrique, etc.). Dans le cadre de cette thèse, nous nous efforçons à présenter les résultats sous la forme de compromis multi-objectifs.
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Ngwanya, Olwethu. "Molecularly imprinted polymers for detection of volatile organics associated with fuel combustion." University of the Western Cape, 2018. http://hdl.handle.net/11394/6363.
Full textAbstract:
Magister Scientiae - MSc (Chemistry)Pollutants such as polycyclic aromatic hydrocarbons (PAHs) are known for their toxic effects which may lead to the cause of degenerative diseases in both humans and animals. PAHs are widespread in the environment, and may be found in water, food, automotive industry and petrochemical industries to name but a few sources. Literature reports have highlighted industrial workplace exposure to PAHs as a leading cause for development of cancer in workers. Particularly, workers in the petrochemical industry are adversely affected and the incidence of skin and lung cancer in this population group is high. The United States of America in its guidelines developed by environmental protection agency (EPA) has identified 18 PAHs as priority pollutants. Among these are anthracene, benzo[a]pyrene and pyrene which have been selected as the focal point of this study due to their significance in the petrochemical industry. Due to the carcinogenic and mutagenic properties reported in literature for certain PAHs, there have been monitoring procedures taken in most countries around the world. The commonly used analytical methods for the detection of PAHs from industrial samples are high performance liquid chromatography (HPLC) coupled to fluorescence detection, membrane filtration, ozonation and reverse osmosis. Analysis of PAHs from the petrochemical industry is typically performed by HPLC method as well as sono-degredation in the presence of oxygen and hydrogen peroxide.
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Heard, Kane. "Novel polyaromatics for organic electronics and graphene exfoliation : synthetic approaches utilising regioselective aromatic C-H borylation." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/novel-polyaromatics-for-organic-electronics-and-graphene-exfoliation-synthetic-approaches-utilising-regioselective-aromatic-ch-borylation(f8cd1879-521e-41f6-8a3c-2af7add7844b).html.
Full textAbstract:
Projects were undertaken investigating the functionalisation of polyaromatic cores (chrysene, pyrene and perylene) for use in organic electronics and aqueous graphene stabilisation. In each case an iridium-catalysed aromatic C-H borylation formed a key synthetic step, allowing access to unique substitution patterns. The development of strategies for the orthogonal and asymmetric functionalisation of polyaromatic hydrocarbons was explored. In a key synthetic step 4,10-dichlorochrysene was regioselectively borylated in high yields at the 2,8-positions though C-H activation chemistry. The subsequent application of sequential palladium-catalysed Suzuki and Kumada coupling reactions to this intermediate enabled the synthesis of a series of chrysene derivatives with a unique orthogonal "A2B2" 2,8- and 4,10-substitution pattern. In addition the application of a trifluoromethylation at the borylated 2,8-positions enabled the synthesis of a donor-acceptor chrysene derivative. The effect of these substitution patterns on the photophysical and electrochemical properties of these derivatives was investigated and their potential use as organic semiconducting materials evaluated. In particular the synthesised chrysene derivatives displayed broadened UV-vis absorption spectra, redshifted fluorescence spectra, increased HOMO levels and decreased band gaps. In an extension of these aromatic substitution methodologies, pyrene and perylene aromatic cores were functionalised to perform as stabilisers for aqueous graphene dispersions, investigating asymmetric motifs that may maximise performance. A series of amphiphilic pyrene- and perylene-based alkylsulfonic acid salts were synthesised via their intermediate hydroxyalkyl derivatives. In addition the application of the previously explored aromatic C-H borylation allowed access to 7- and 5,8,11- asymmetrically substituted pyrene and perylene derivatives. Through collaboration, initial steps have been undertaken to compare and evaluate these novel stabilisers for their ability exfoliate graphite to graphene in aqueous solution.
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Schmidt, Karin. "Electronic excited states in quasi- one- dimensional organic solids with strong coupling of Frenkel and charge-transfer excitons." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2003. http://nbn-resolving.de/urn:nbn:de:swb:14-1048602425703-44009.
Full textAbstract:
This work offers a concept to predict and comprehend the electronic excited states in regular aggregates formed of quasi-one-dimensional organic materials. The tight face-to-face stacking of the molecules justifies the idealization of the crystals and clusters as weakly interacting stacks with leading effects taking place within the columnar sub-structures. Thus, the concept of the small radius exciton theory in linear molecular chains was adopted to examine the excitonic states. The excited states are composed of molecular excitations and nearest neighbor charge transfer (CT) excitations. We analyzed the structure and properties of the excited states which result from the coupling of Frenkel and CT excitons of arbitrary strength in finite chains with idealized free ends. With the help of a partially analytical approach to determine the excitonic states of mixed Frenkel CT character by introducing a complex wave vector, two main types of states can be distinguished. The majority of states are bulk states with purely imaginary wavevector. The dispersion relation of these state matches exactly the dispersion relation known from the infinite chain. The internal structure of the excitons in infinite chains is directly transferred to the bulk states in finite chains. TAMM-like surface states belong to the second class of states. Owing to the damping mediated by a a non-vanishing real part of the wavevector, the wave function of the surface states is localized at the outermost molecules. The corresponding decay length is exclusively determined by the parameterization of the coupling and is independent of the system size. It can therefore be assigned as a characteristic quantum length which plays a vital role for the understanding of system-dependent behavior of the states. The number and type of surface states occurring is predicted for any arbitrary coupling situation. The different nature of bulk and surface states leads to distinct quantum confinement effects. Two regimes are distinguished. The first regime, the case of weak confinement, is realized if the chain length is larger than the intrinsic length. Both kinds of states arrange with the system size according to their nature. Derived from the excitonic states of the infinite chain, the bulk states preserve their quasi-particle character in these large systems. Considered as a quasi-particle confined in box, they change their energy with the system size according to the particle-in-a-box picture. The surface states do not react to a change of the chain length at all, since effectively only the outermost molecules contribute to the wavefunction. The second regime holds if the states are strongly confined, i.e., the system is smaller than the intrinsic length. Both types of states give up their typical behavior and adopt similar propertiesDiese Arbeit unterbreitet ein Konzept, um elektronische Anregungszustände in Aggregaten quasi-eindimensionaler organischer Materialien vorherzusagen und zu verstehen. Die dichte Packung der Moleküle rechtfertigt die Idealisierung der Kristalle bzw. Cluster als schwach wechselwirkende Stapel, wobei die führenden Effekte innerhalb der Molekülstapel zu erwarten sind. Zur Beschreibung der exzitonischen Zustände wurde das Konzept der 'small radius'-Exzitonen in linearen Molekülketten angewandt. Die elektronischen Zustände sind dabei aus molekularen (Frenkel) und nächsten Nachbarn 'charge-transfer' (CT) Anregungen zusammengesetzt. Die Struktur und Eigenschaften der Zustände wurden für beliebige Kopplungsstärken zwischen Frenkel- und CT Anregungen in Ketten mit idealisierten freien Enden für beliebiger Längen analysiert. Der entwickelte, überwiegend analytische Zugang, welcher auf der Einführung eines komplexen Wellenvektors beruht, ermöglicht die Unterscheidung zweier grundsätzlicher Zustandstypen. Die Mehrheit der Zustände sind Volumenzustände mit rein imaginärem Wellenvektor. Die zugehörige Dispersionsrelation entspricht exakt der Dispersionsrelation der unendlichen Kette mit äquivalenten Kopplungsverhältnissen. Die interne Struktur der Exzitonen der unendlichen Kette wird auf die Volumenzustände der endlichen Kette direkt übertragen. Der zweite grundlegende Zustandstyp umfaßt Tamm-artige Oberflächenzustände. Aufgrund der durch einen nichtverschwindenden reellen Anteil des Wellenvektors hervorgerufenen Dämpfung sind die Wellenfunktionen der Oberflächenzustände an den Randmolekülen lokalisiert. Die entsprechende Dämpfungslänge ist ausschließlich durch die Parametrisierung der Kopplungen bestimmt und ist somit unabhängig von der Kettenlänge. Sie kann daher als intrinische Quantenlänge interpretiert werden, welche von essentieller Bedeutung für das Verständnis systemgrößenabhängigen Verhaltens ist. Sowohl die Anzahl als auch die Art der Oberflächenzustände kann für jede Kopplungssituation vorhergesagt werden. Die unterschiedliche Natur der Volumen- und Oberflächenzustände führt auf ausgeprägte 'Quantum confinement' Effekte. Zwei Regime sind zu unterscheiden. Im Falle des ersten Regimes, dem schwachen 'Confinement', ist die Kettenlänge größer als die intrinsische Länge. Beide Zustandarten reagieren auf eine Veränderung der Kettenlänge gemäß ihrer Natur. Aufgrund ihrer Verwandschaft mit den Bandzuständen der unendlichen Kette bewahren die Volumenzustände ihren Quasiteilchen-Charakter. Aufgefaßt als Quasiteilchen, erfahren sie in endlichen Systemen eine energetische Verschiebung gemäß dem Potentialtopf-Modell. Oberflächenzustände zeigen keine Reaktion auf veränderte Kettenlängen, da effektiv nur die Randmoleküle zur Wellenfunktion beitragen. Es findet ein Übergang zum zweiten Regime (starkes 'Confinement') statt, sobald die Kettenlänge kleiner als intrinsische Quantenlänge wird. Beide Zustandsarten geben ihr typisches Verhalten auf und werden mit abnehmender Kettenlänge zunehmend ähnlicher
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Schmidt, Karin. "Electronic excited states in quasi- one- dimensional organic solids with strong coupling of Frenkel and charge-transfer excitons." Doctoral thesis, Technische Universität Dresden, 2002. https://tud.qucosa.de/id/qucosa%3A24207.
Full textAbstract:
This work offers a concept to predict and comprehend the electronic excited states in regular aggregates formed of quasi-one-dimensional organic materials. The tight face-to-face stacking of the molecules justifies the idealization of the crystals and clusters as weakly interacting stacks with leading effects taking place within the columnar sub-structures. Thus, the concept of the small radius exciton theory in linear molecular chains was adopted to examine the excitonic states. The excited states are composed of molecular excitations and nearest neighbor charge transfer (CT) excitations. We analyzed the structure and properties of the excited states which result from the coupling of Frenkel and CT excitons of arbitrary strength in finite chains with idealized free ends. With the help of a partially analytical approach to determine the excitonic states of mixed Frenkel CT character by introducing a complex wave vector, two main types of states can be distinguished. The majority of states are bulk states with purely imaginary wavevector. The dispersion relation of these state matches exactly the dispersion relation known from the infinite chain. The internal structure of the excitons in infinite chains is directly transferred to the bulk states in finite chains. TAMM-like surface states belong to the second class of states. Owing to the damping mediated by a a non-vanishing real part of the wavevector, the wave function of the surface states is localized at the outermost molecules. The corresponding decay length is exclusively determined by the parameterization of the coupling and is independent of the system size. It can therefore be assigned as a characteristic quantum length which plays a vital role for the understanding of system-dependent behavior of the states. The number and type of surface states occurring is predicted for any arbitrary coupling situation. The different nature of bulk and surface states leads to distinct quantum confinement effects. Two regimes are distinguished. The first regime, the case of weak confinement, is realized if the chain length is larger than the intrinsic length. Both kinds of states arrange with the system size according to their nature. Derived from the excitonic states of the infinite chain, the bulk states preserve their quasi-particle character in these large systems. Considered as a quasi-particle confined in box, they change their energy with the system size according to the particle-in-a-box picture. The surface states do not react to a change of the chain length at all, since effectively only the outermost molecules contribute to the wavefunction. The second regime holds if the states are strongly confined, i.e., the system is smaller than the intrinsic length. Both types of states give up their typical behavior and adopt similar properties.Diese Arbeit unterbreitet ein Konzept, um elektronische Anregungszustände in Aggregaten quasi-eindimensionaler organischer Materialien vorherzusagen und zu verstehen. Die dichte Packung der Moleküle rechtfertigt die Idealisierung der Kristalle bzw. Cluster als schwach wechselwirkende Stapel, wobei die führenden Effekte innerhalb der Molekülstapel zu erwarten sind. Zur Beschreibung der exzitonischen Zustände wurde das Konzept der 'small radius'-Exzitonen in linearen Molekülketten angewandt. Die elektronischen Zustände sind dabei aus molekularen (Frenkel) und nächsten Nachbarn 'charge-transfer' (CT) Anregungen zusammengesetzt. Die Struktur und Eigenschaften der Zustände wurden für beliebige Kopplungsstärken zwischen Frenkel- und CT Anregungen in Ketten mit idealisierten freien Enden für beliebiger Längen analysiert. Der entwickelte, überwiegend analytische Zugang, welcher auf der Einführung eines komplexen Wellenvektors beruht, ermöglicht die Unterscheidung zweier grundsätzlicher Zustandstypen. Die Mehrheit der Zustände sind Volumenzustände mit rein imaginärem Wellenvektor. Die zugehörige Dispersionsrelation entspricht exakt der Dispersionsrelation der unendlichen Kette mit äquivalenten Kopplungsverhältnissen. Die interne Struktur der Exzitonen der unendlichen Kette wird auf die Volumenzustände der endlichen Kette direkt übertragen. Der zweite grundlegende Zustandstyp umfaßt Tamm-artige Oberflächenzustände. Aufgrund der durch einen nichtverschwindenden reellen Anteil des Wellenvektors hervorgerufenen Dämpfung sind die Wellenfunktionen der Oberflächenzustände an den Randmolekülen lokalisiert. Die entsprechende Dämpfungslänge ist ausschließlich durch die Parametrisierung der Kopplungen bestimmt und ist somit unabhängig von der Kettenlänge. Sie kann daher als intrinische Quantenlänge interpretiert werden, welche von essentieller Bedeutung für das Verständnis systemgrößenabhängigen Verhaltens ist. Sowohl die Anzahl als auch die Art der Oberflächenzustände kann für jede Kopplungssituation vorhergesagt werden. Die unterschiedliche Natur der Volumen- und Oberflächenzustände führt auf ausgeprägte 'Quantum confinement' Effekte. Zwei Regime sind zu unterscheiden. Im Falle des ersten Regimes, dem schwachen 'Confinement', ist die Kettenlänge größer als die intrinsische Länge. Beide Zustandarten reagieren auf eine Veränderung der Kettenlänge gemäß ihrer Natur. Aufgrund ihrer Verwandschaft mit den Bandzuständen der unendlichen Kette bewahren die Volumenzustände ihren Quasiteilchen-Charakter. Aufgefaßt als Quasiteilchen, erfahren sie in endlichen Systemen eine energetische Verschiebung gemäß dem Potentialtopf-Modell. Oberflächenzustände zeigen keine Reaktion auf veränderte Kettenlängen, da effektiv nur die Randmoleküle zur Wellenfunktion beitragen. Es findet ein Übergang zum zweiten Regime (starkes 'Confinement') statt, sobald die Kettenlänge kleiner als intrinsische Quantenlänge wird. Beide Zustandsarten geben ihr typisches Verhalten auf und werden mit abnehmender Kettenlänge zunehmend ähnlicher.
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Shi, Ming Yu. "Organic logic circuits : fabrication process and device optimisation." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/organic-logic-circuits-fabrication-process-and-device-optimisation(6dee3a75-f681-4493-9a06-68462bd58fe9).html.
Full textAbstract:
Initial research in the field of organic electronics focused primarily on the improvements in material performance. Significant progress has been achieved in the case of organic field effect transistors, where reported mobility values are now over 5 orders of magnitude higher than those of early devices. As a consequence, the use of organic transistors is now being considered for real-world applications in the form of integrated logic circuits. This in turn presents many new challenges, as the logic circuit requirements are more demanding on the transistor characteristics and corresponding fabrication processes. This thesis investigates the feasibility of organic technology for its potential use in future low-cost, high-volume electronic applications. The research objectives were accomplished by practical evaluation of an organic logic circuit fabrication process. First, recent advances in the fabrication of organic circuits in terms of transistor structure, material usage and fabrication techniques are reviewed. Next, a lithographic logic circuit fabrication process using PVP gate dielectric and TIPS-pentacene organic semiconductor adapted from state of the art fabrication process is presented. The logic circuit design decisions and the methodology for the fabrication process are thoroughly documented. Using this process, zero-Vgs and diode-load inverter circuits were successfully fabricated. However, the process is in need of further refinement for more complex circuit designs, as the fabrication of a comparator circuit consisting of 11 transistors was unsuccessful. Two optimisation techniques that are compatible with the logic circuit fabrication process were also explored in this work. To improve the capacitive coupling of the dielectric layer, the use of a polymer nanocomposite dielectric was investigated. The nanocomposite is prepared by blending PVP solution with a high-k inorganic nanoparticle filler, barium strontium titanate. Using the nanocomposite dielectric, both single transistors and integrated logic circuits were successfully fabricated. This is the first report on the use of PVP and barium strontium titanate nanocomposite dielectric with a lithographic based logic circuit fabrication process. The use of PFBT modified Au contacts for the fabrication process was investigated to improve theperformance of the contact electrode layer. Using PFBT, mobility increased by one order of magnitude over untreated Au electrodes for the PVP and TIPS-pentacene transistors.
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Torres, Miranda Miguel Angel. "Conception de circuits analogiques et numériques avec des transistors organiques flexibles." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066693/document.
Full textAbstract:
Dans l’âge des objets connectés, circuits conventionnels implémenté sur silicium ne sont pas la seule option pour réaliser des interfaces des capteurs. Dispositifs électroniques implémentés sur substrats souples sont aussi une option intéressante comme interface des capteurs dans notre quotidien, e.g: dans des vêtements, emballages, peau et dedans notre corps humain. Dans cette thèse nous proposons une formalisation de :-La procédure de fabrication de transistors en utilisant des matériaux organiques et flexibles. -La conception de circuits analogiques et numériques en utilisant ces transistors. Les contributions de cette thèse sont :• Optimisation de la procédure de fabrication et caractérisation de 2 technologies : la première fabriqué en utilisant des masques (« shadow masks » en anglais) avec un procès relativement « simple à implémenter ». La deuxième par un procès en utilisant la photolithographie et l’auto alignement. • Modélisation et extraction de paramètres pour prévoir leurs variations dans la conception de circuits.• Customisation des outils CAO « Open Source » VLSI (Alliance ©) pour la conception des circuits et layouts des transistors organiques.• Conception, fabrication et mesure des circuits analogiques (OTAs, comparateurs et convertisseurs analogiques-numériques) et circuits numériques simples (inverseurs, portes logiques, bascules). Ce travail a eu des résultats intéressants et il ouvre un ample spectre d’applications dans l’avenir dans le domaine de l’électronique flexible et organiqueIn the era of “Internet of Things”, conventional silicon-based circuits are not the only option to realize sensor interfaces. Electronic devices based on flexible materials are an interesting approach to interface with sensors connected to our everyday life, e.g.: clothes, packages, skin and into the human body. In this thesis, we propose a formalization of the:- Transistor fabrication process using organic and flexible materials.- Analog and digital circuit design using these transistors. The main contribution of this work can be summarized in the following:- Optimization of the fabrication and characterization process of two technologies: the first by shadow masks with an easy-to-fabricate procedure, the second by self-alignment and photolithography.- Modeling and parameter extraction for process variation aware analog design.- Customization of an open source VLSI CAD tools (Alliance©) for circuit design and layout of OTFT.- Design, fabrication and measurement of OTFT analog front-ends (OTAs, Comparators, Analog-to-Digital Converters,…) and basic digital circuits (Inverters, Logic Gates, …).This work achieved very interesting results and it opens a wide scope of future applications in the field of Flexible organic electronics
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Günther, Alrun Aline. "Vertical Organic Field-Effect Transistors." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-207731.
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Diese Arbeit stellt eine eingehende Studie des sogenannten Vertikalen Organischen Feld-Effekt-Transistors (VOFET) dar, einer neuen Transistor-Geometrie, welche dem stetig wachsenden Bereich der organischen Elektronik entspringt. Dieses neuartige Bauteil hat bereits bewiesen, dass es in der Lage ist, eine der fundamentalen Einschränkungen herkömmlicher organischer Feld-Effekt-Transistoren (OFETs) zu überwinden: Die für Schaltfrequenz und An-Strom wichtige Kanallänge des Transistors kann im VOFET stark reduziert werden, ohne dass teure und komplexe Strukturierungsmethoden genutzt werden müssen. Das genaue Funktionsprinzip des VOFET ist bisher jedoch weitgehend unerforscht. Durch den Vergleich von experimentellen Daten mit Simulationsdaten des erwarteten Bauteil-Verhaltens wird hier ein erstes, grundlegendes Verständnis des VOFETs erarbeitet. Die so gewonnenen Erkenntnisse werden im Folgenden genutzt, um bestimmte Parameter des VOFETs kontrolliert zu manipulieren. So wird beispielsweise gezeigt, dass die Morphologie des organischen Halbleiters, und damit seine Abscheidungsparameter, sowohl für die VOFET-Herstellung als auch für den Ladungsträgertransport im fertigen Bauteil eine wichtige Rolle spielen. Weiterhin wird gezeigt, dass der VOFET, genau wie der konventionelle OFET, durch das Einbringen von Kontaktdotierung deutlich verbessert werden kann. Mit Hilfe dieser Ergebnisse kann gezeigt werden, dass das Funktionsprinzip des VOFETs mit dem eines konventionellen OFETs nahezu identisch ist, wenn man von geringen Abweichungen aufgrund der unterschiedlichen Geometrien absieht. Basierend auf dieser Erkenntnis wird schließlich ein VOFET präsentiert, welcher im Inversionsmodus betrieben werden kann und so die Lücke zur konventionellen MOSFET-Technologie schließt. Dieser Inversions-VOFET stellt folglich einen vielversprechenden Ansatz für leistungsfähige organische Transistoren dar, welche als Grundbausteine für komplexe Elektronikanwendungen auf flexiblen Substraten genutzt werden könnenThis work represents a comprehensive study of the so-called vertical organic field-effect transistor (VOFET), a novel transistor geometry originating from the fast-growing field of organic electronics. This device has already demonstrated its potential to overcome one of the fundamental limitations met in conventional organic transistor architectures (OFETs): In the VOFET, it is possible to reduce the channel length and thus increase On-state current and switching frequency without using expensive and complex structuring methods. Yet the VOFET's operational principles are presently not understood in full detail. By simulating the expected device behaviour and correlating it with experimental findings, a basic understanding of the charge transport in VOFETs is established and this knowledge is subsequently applied in order to manipulate certain parameters and materials in the VOFET. In particular, it is found that the morphology, and thus the deposition parameters, of the organic semiconductor play an important role, both for a successful VOFET fabrication and for the charge transport in the finished device. Furthermore, it is shown that VOFETs, just like their conventional counterparts, are greatly improved by the application of contact doping. This result, in turn, is used to demonstrate that the VOFET essentially works in almost exactly the same way as a conventional OFET, with only minor changes due to the altered contact arrangement. Working from this realisation, a vertical organic transistor is developed which operates in the inversion regime, thus closing the gap to conventional MOSFET technology and providing a truly promising candidate for high-performance organic transistors as the building blocks for advanced, flexible electronics applications
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Pereira, Wanderson Adriano Biscola [UNESP]. "Intoxicação cúprica experimental em ovinos: aspectos clínicos e laboratoriais." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/101265.
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pereira_wab_dr_jabo.pdf: 854556 bytes, checksum: 9d7af941da3e924cbf09a5ce3f63ef48 (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Os ovinos possuem tendência a acumular cobre no organismo. Quando a capacidade de armazenagem hepática se esgota, o cobre é liberado para o sangue causando sinais clínicos da intoxicação. Para verificar as alterações presentes na bioquímica sérica, hemograma, morfologia eritrocitária, perfil de proteínas séricas e concentração de cobre sérico, durante as fases pré-hemolítica e hemolítica da intoxicação crônica por cobre, foram utilizados seis ovinos distribuídos aleatoriamente em dois grupos: G-1 (controle) e G-2 (experimentalmente intoxicados). Os três ovinos do G-2, além da dieta diária receberam 3mg de CuSO4. 5H2O/Kg PV, seguido de aumentos semanais de 3mg de CuSO4. 5H2O/ Kg PV na dose diária. Diariamente realizou-se o exame físico dos ovinos de ambos os grupos. Para obtenção do hemograma e dos componentes bioquímicos sanguíneos foram colhidas amostras com antes (M0 – M3), durante (M4) e após (M5 e M6) a crise hemolítica. Foram realizadas necropsias dos ovinos do G-2 que morreram e dos ovinos do G-1, submetidos à eutanásia ao fim do experimento e fragmentos do fígado desses animais foram colhidos para avaliação histopatológica. Durante a fase pré-hemolítica evidenciaram-se poucas alterações, entretanto durante a crise hemolítica os ovinos do G-2 apresentaram anemia macrocítica normocrômica, predomínio de hemácias com morfologia de acantócitos, leucocitose por neutrofilia, elevação nas atividades séricas de AST,GGT, CK e hipercupremia; Os teores séricos de ceruloplasmina apresentaram-se diminuídos e os teores de transferrina, proteína de 35.000 Da e IgG de cadeia leve apresentaramse aumentados no M2; os animais intoxicados apresentaram anorexia, membranas mucosas ictéricas, fezes amolecidas de coloração verde-escura e hemoglobinúria. À necropsia observou-se mucosas, fígado e demais tecidos de coloração amarelada...
Sheep have a tendency to accumulate copper in the body. When the liver storage capacity is exhausted, copper is released into the blood causing clinical signs of poisoning. Six lambs fed a basal diet were randomly assigned to 2 groups: G - 1 (control) and G-2 (experimentally intoxicated). The three sheep of the G-2, were drenched initially with 3 mg of CuSO4. 5H2O/ kg bw daily for a week. Every week an additional dose of 3mg CuSO4. 5H2O/ kg bw was included in the drench until signs of copper poisoning appeared. Every day, the lambs were monitored clinically. before (M0 – M3), during (M4) and after (M5 and M6) to hemolytic crisis, sample blood were obtained for biochemical analysis of AST, GGT and CK, blood count, serum proteins and serum concentration of copper. The lambs of the G-2 that died in the course of the experiment and the lambs of the G-1 euthanized at the end, were necropsied and fragments of liver, were obtained for histopathology. During the pre-hemolytic phase few changes were evidenced, however thought the hemolytic crisis the sheep of the G-2 were presented macrocytic normochromic anemia, a predominance of erythrocytes with acantocytes morphology, leukocytosis by neutrophilia, elevation in serum activities of AST, GGT and CK and hipercupremia; Serum levels of ceruloplasmin was presented reduced and the levels of transferrin, 35,000 of protein and IgG- light chain were increased in M2; the lambs of G-2 exhibited anorexia, jaundiced mucous membranes, soften and dark-green feces and hemoglobinuria. Gross examination of poisoned lambs revealed mucous membranes, liver and other tissues yellowish, dark kidneys and brownish urine. Histopathology of the liver showed megalocitose of hepatocytes, the disorganization of strands of hepatocytes, cholestasis and inflammatory infiltrate lymphocytic peri-portal.
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Martinez, Garcia Alba Maria. "Study of the Resistive Switching Mechanism in Novel Ultra-thin Organic-inorganic Dielectric-based RRAM through Electrical Observations." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299358.
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The promising role resistive random-access memory (RRAM) plays in the imminent reality of wearable electronics calls for a new, updated physical model of their operating mechanism. Their high applicability as the next-generation flexible non-volatile memory (NVM) devices has promoted the recent emergence of a novel ultra-thin (< 5nm) organic/inorganic hybrid dielectric RRAM. A deep understanding of their resistive switching (RS) behavior is required to unlock their suitability in future electronics applications. However, the extremely reduced thicknesses bring about new challenges in terms of material characterization sample processing, while the RS observations through electrical characterization techniques lack uniformity in the key switching parameters, thus hindering the identification of any clear trends. This work studies the RS mechanism in ultra-thin Al/Hf-hybrid/Ni RRAM devices through uniformity-improved electrical observations. First, the focus is to implement a ramped-pulse train method during the reset process to reduce the dispersion of the voltage and resistance fluctuations at different starting voltage amplitudes and pulse widths. After finding the optimal electrical programming conditions for reduced parameter dispersions, a temperature test was performed to study the contributions of the metal ions and oxygen vacancies (V2+) in the switching layer. Finally, a physical model describing the operating mechanism in flexible RRAM is proposed after the close observation and study of the processed devices. The model is based on the coexistence of a hetero-metallic portion composed of Al and Hf3Al2, and a V2+ portion connected to form the hybrid conducting filament (CF) and turning the device on. The CF forming processes emphasize the strong presence of these vacancies partaking in RS, as the temperature dependence results suggest the majority of their concentration to be generated during this step. Also, the different electrical potential, temperature, and concentration gradients influencing the V2+ migration during RS may explain some of the failure mechanisms in the rupture and the re-forming of the filament. Additionally, the possible presence of a thin Al-oxide layer in the Al/Hf-hybrid interface may give a reason for leaky on-states. A detailed physical model of the RS mechanism in next-generation flexible RRAMs is key to learn to unlock a range of emerging technologies fitted to today’s needs.Den senaste introduktionen av ultratunn (<5 nm) organisk-oorganisk hybrid dielektrisk RRAM som nästa generations icke-flyktiga minnesenheter kräver en djup förståelse för hybridskiktresistiv växling (RS). Den extremt reducerade tjockleken hindrar emellertid deras bearbetbarhet för materialkarakteriseringstekniker. Dessutom hindrar den dåliga enhetligheten i viktiga omkopplingsparametrar fortfarande i RRAM att alla trender kan definieras tydligt genom elektrisk karakterisering. Detta arbete använder elektrisk manipulation genom en RPS-metod (ramped-pulse series) för att förbättra spännings- och motståndsfluktuationerna i återställningsprocessen för ultratunna Al/Hf-hybrid/Ni-enheter vid olika spänningsamplitud, pulsbredd och temperaturförhållanden. Från de erhållna RPS-optimerade resultaten föreslås en ny och detaljerad fysisk modell som beskriver driftsmekanismen. Samexistensen i den ledande filamenten (CF) av en hybridmetalldel, sammansatt av Al och Hf3Al2, och en syrevakansdel bekräftas. Vår modell betonar vakansbidraget i RS, där majoriteten genereras under CF-formningsprocessen och deltar i olika grad i filamentbrottet för RPS och ingen RPS-bearbetade enheter via Joule-uppvärmning, drift och Fick-krafter. Dessutom förklaras kopplingsfelhändelser baserat på närvaron av ett Al2O3-lager i Al/Hf-hybridgränssnittet.
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Lindh, Mattias. "Inkjet deposition of electrolyte : Towards Fully Printed Light-emitting Electrochemical Cells." Thesis, Umeå universitet, Institutionen för fysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-80272.
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Organic electronics is a hot and modern topic which holds great promise for present and future applications. One such application is the light-emitting electrochemical cell (LEC). It can be fully solution processed and driven at low voltage providing light emission from a large surface. Inkjet printers available today can print a variety of inks, both solutions and dispersions. The technique is scalable and a quick and easy way to accurately deposit small quantities of material in user definable patterns onto a substrate. This is desirable to make low cost and efficient optical devices like displays. In this thesis it has been shown that solid electrolytes, after being dissolved in a liquid solvent, can be inkjet printed into a set of well separated distinct drops with an average maximum thickness of 150 nm. The electrolytes are commonly used in LECs and comprised by poly(ethylene glycol) with molar masses ranging from 1 – 35 kg/mol, and potassium trifluoromethanesulfonate (KCF3 SO3 )—together dissolved incyclohexanone to form an ink. The smallest achieved edge to edge distance between the printed drops was 40 μm. Together with a drop diameter of 50 μm it yields a coverage of 24% at a resolution of 280 dpi. Profiles of dried deposited drops of electrolyte were examined with a profilometer, which showed adistinct coffee ring effect on each drop. In particular, the ridges of the coffee rings were broken into pillar like shapes, together forming a structure akin to a scandinavian ancient remnant called stone ship. Different drop diameters were measured in and between the indium tin oxide samples. The drops’ speeds and sizes atejection from the nozzles seemed unchanged, and wettability is most probably the physical phenomena tolook into in order to understand what generates the differences. Local changes in surface roughness and/or surface energy, possibly originating from the cleaning process of the samples, is most likely the cause. No indications towards large differences in surface tension between the printable inks were seen, however their viscoelastic properties were not measured. As part of the thesis work a LEC characterization set-up was built. It drives a LEC at constant currentand measures the driving voltage, -current, and luminance over time. The set-up is controlled by a Labview virtual instrument and the data exported to a text-file for later analysis. The precision of the luminance measurements is ±0.1 cd/m2 for readings < 50 cd/m2 , but the accuracy is uncertain. The conclusion of this thesis is that it is indeed possible to print solid electrolytes dissolved in cyclo-hexanone with an inkjet printer. However, in order to fully understand the spreading and drying of thedrops, studies of the inks’ viscoelastic properties, together with surface roughness and -energy density ofthe substrates, are needed. The largest molar mass of nicely printable poly(ethylene glycol), at an ink concentration of 10 mg/ml, was 35 kg/mol. This is comparable to the molar mass of an active light-emittingmaterial, “SuperYellow”, often used in LECs. Even though their respective molecular structures are very different, this indicates that inkjet printing of complete LEC-inks, containing both the active material and solid electrolyte, is feasible. Most probably it would require substantial tuning of the printing parameters. This thesis provides further hope for future fully inkjet printed LECs.
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Pereira, Wanderson Adriano Biscola. "Intoxicação cúprica experimental em ovinos : aspectos clínicos e laboratoriais /." Jaboticabal : [s.n.], 2008. http://hdl.handle.net/11449/101265.
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Orientador: Mário Roberto HataydeBanca: Pierre Castro Soares
Banca: Humberto Eustáquio Coelho
Banca: José Jurandir Fagliari
Banca: Antônio Carlos Alessi
Resumo: Os ovinos possuem tendência a acumular cobre no organismo. Quando a capacidade de armazenagem hepática se esgota, o cobre é liberado para o sangue causando sinais clínicos da intoxicação. Para verificar as alterações presentes na bioquímica sérica, hemograma, morfologia eritrocitária, perfil de proteínas séricas e concentração de cobre sérico, durante as fases pré-hemolítica e hemolítica da intoxicação crônica por cobre, foram utilizados seis ovinos distribuídos aleatoriamente em dois grupos: G-1 (controle) e G-2 (experimentalmente intoxicados). Os três ovinos do G-2, além da dieta diária receberam 3mg de CuSO4. 5H2O/Kg PV, seguido de aumentos semanais de 3mg de CuSO4. 5H2O/ Kg PV na dose diária. Diariamente realizou-se o exame físico dos ovinos de ambos os grupos. Para obtenção do hemograma e dos componentes bioquímicos sanguíneos foram colhidas amostras com antes (M0 - M3), durante (M4) e após (M5 e M6) a crise hemolítica. Foram realizadas necropsias dos ovinos do G-2 que morreram e dos ovinos do G-1, submetidos à eutanásia ao fim do experimento e fragmentos do fígado desses animais foram colhidos para avaliação histopatológica. Durante a fase pré-hemolítica evidenciaram-se poucas alterações, entretanto durante a crise hemolítica os ovinos do G-2 apresentaram anemia macrocítica normocrômica, predomínio de hemácias com morfologia de acantócitos, leucocitose por neutrofilia, elevação nas atividades séricas de AST,GGT, CK e hipercupremia; Os teores séricos de ceruloplasmina apresentaram-se diminuídos e os teores de transferrina, proteína de 35.000 Da e IgG de cadeia leve apresentaramse aumentados no M2; os animais intoxicados apresentaram anorexia, membranas mucosas ictéricas, fezes amolecidas de coloração verde-escura e hemoglobinúria. À necropsia observou-se mucosas, fígado e demais tecidos de coloração amarelada... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Sheep have a tendency to accumulate copper in the body. When the liver storage capacity is exhausted, copper is released into the blood causing clinical signs of poisoning. Six lambs fed a basal diet were randomly assigned to 2 groups: G - 1 (control) and G-2 (experimentally intoxicated). The three sheep of the G-2, were drenched initially with 3 mg of CuSO4. 5H2O/ kg bw daily for a week. Every week an additional dose of 3mg CuSO4. 5H2O/ kg bw was included in the drench until signs of copper poisoning appeared. Every day, the lambs were monitored clinically. before (M0 - M3), during (M4) and after (M5 and M6) to hemolytic crisis, sample blood were obtained for biochemical analysis of AST, GGT and CK, blood count, serum proteins and serum concentration of copper. The lambs of the G-2 that died in the course of the experiment and the lambs of the G-1 euthanized at the end, were necropsied and fragments of liver, were obtained for histopathology. During the pre-hemolytic phase few changes were evidenced, however thought the hemolytic crisis the sheep of the G-2 were presented macrocytic normochromic anemia, a predominance of erythrocytes with acantocytes morphology, leukocytosis by neutrophilia, elevation in serum activities of AST, GGT and CK and hipercupremia; Serum levels of ceruloplasmin was presented reduced and the levels of transferrin, 35,000 of protein and IgG- light chain were increased in M2; the lambs of G-2 exhibited anorexia, jaundiced mucous membranes, soften and dark-green feces and hemoglobinuria. Gross examination of poisoned lambs revealed mucous membranes, liver and other tissues yellowish, dark kidneys and brownish urine. Histopathology of the liver showed megalocitose of hepatocytes, the disorganization of strands of hepatocytes, cholestasis and inflammatory infiltrate lymphocytic peri-portal.
Doutor
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TOMINAGA, FLAVIO K. "Efeito da irradiação na toxicidade de fármacos em solução aquosa: cloridrato de fluoxetina, diclofenaco de sódio e mistura de ambos." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26825.
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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-11-11T16:56:25Z
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As evidências da contaminação das águas por resíduos de medicamentos e seus subprodutos levou esse grupo de resíduos a compor a lista de poluentes orgânicos emergentes, como consequência da expansão do uso de medicamentos, como o antidepressivo cloridrato de fluoxetina e o anti-inflamatório diclofenaco. Diversos Processos Oxidativos Avançados vêm sendo aplicados para a degradação destes compostos. Dentre eles, o processo de irradiação com feixe elétrons obteve bons resultados na remoção de toxicidade e degradação de fármacos. O presente estudo consistiu em aplicar radiação ionizante como uma possível tecnologia para degradar os fármacos em águas. A irradiação de solução aquosa contendo os fármacos foi aplicada usando acelerador de elétrons, cuja eficiência foi discutida mediante análises químicas (Cromatografia Líquida Ultra Rápida e Carbono Orgânico Total (COT)), ecotoxicológicas (ensaios de toxicidade com Vibrio fischeri e Daphnia similis) e biológicas (Ensaios Respirométricos). Os resultados de COT indicaram mineralização não significativa dos compostos, mesmo sendo observada degradação máxima de 99,9% para o diclofenaco e 55% para o cloridrato de fluoxetina na mistura (1:1) em 5.0 kGy. Foi observada toxicidade aguda dos fármacos, sendo mais acentuada para a fluoxetina, seguido do diclofenaco e, finalmente, da mistura para V. fischeri. Quando D. similis foram empregadas nessa avaliação, a ordem de toxicidade foi de fluoxetina, a mistura de ambos os medicamentos e do diclofenaco. Além disso, foi observada remoção de toxicidade nas amostras irradiadas em todas as doses aplicadas para a bactéria V. fischeri, com maior eficiência de remoção de toxicidade de 55%, em 5 kGy, na mistura dos dois fármacos. Para a D. similis, foi observada remoção significativa de toxicidade da mistura apenas na dose 2,5 kGy. Os ensaios respiroétricos não indicaram biodegradabilidade após o tratamento.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Cipriano, Thiago de Carvalho. "Nanoestruturas peptídicas como semicondutores ou templates moleculares para eletrônica orgânica." reponame:Repositório Institucional da UFABC, 2016.
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Orientador: Prof. Dr. Wendel Andrade AlvesTese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Nanociências e Materiais Avançados, 2016.
O consumo de produtos eletrônicos pela sociedade provoca forte impacto ambiental no momento de descartar tais eletrônicos. Neste contexto, a busca por materiais ambientalmente amigáveis está alinhada às necessidades de nosso tempo. Nanoestruturas peptídicas derivadas de aminoácidos naturais possuem grande potencial para a fabricação de uma nova geração de dispositivos biodegradáveis, utilizando a rota de síntese de baixo para cima, sem a necessidade de caros processos litográficos. Neste trabalho, nanomateriais peptídicos foram utilizados tanto em sua forma pura quanto modificados com polímeros para a criação de dispositivos eletrônicos. Os efeitos da auto-organização das nanoestruturas sobre o desempenho e eficiência desses dispositivos foram investigados. Transistores orgânicos de efeito de campo (OFETs) baseados no dipeptídeo L,L-difenilalanina foram desenvolvidos pela primeira vez, tendo apresentado razões on/off e mobilidades da ordem de 103 e de 10-3 cm2 Vs-1. Esses valores são bastante promissores na busca de componentes eletrônicos que atendam às necessidades de desempenho atuais. Um diodo orgânico emissor de luz (OLED) também foi fabricado utilizando as nanoestruturas peptídicas de L,L-difenilalanina modificadas com o polímero emissor poli[2,7-(9,9-dioctilfluoreno)]. Embora o dispositivo tenha apresentado eficiência cerca seis vezes menor comparado ao sistema produzidos com o polímero puro, a introdução de peptídeos permitiu o uso de uma quantidade menor de polímero, além de exibir taxas de biodegradabilidade cerca de 85% maiores. A integração de nanoestruturas de peptídeos com dispositivos de eletrônica orgânica pode significar o início do desenvolvimento de materiais biodegradáveis para aplicação em dispositivos com alta demanda de consumo, tendo como consequência a diminuição do impacto ambiental proveniente da utilização destes dispositivos.
The consumption of electronic products in our society leads to strong environmental impact when such devices need to be discarded. In this sense, research on environmental friendly materials is aligned with the needs of our time. Peptide nanostructures derived from natural amino acids have great potential for producing a new generation of biodegradable devices using the "bottom-up" synthesis route without need for expensive lithographic processes. In this work, peptide nanomaterials were used either in pure form or modified with polymers for designing organic electronic devices and the effects of self-organization on performance and efficiency of these devices were investigated. Organic field effect transistors (OFETs) based on the dipeptide L-L-diphenylalanine were developed for the first time, exhibiting on/off and mobility values of the order of 103 and of 10-3 cm2 Vs-1. These values are very promising and meet the current performance needs in organic devices. An organic light emitting diode (OLED) was fabricated using a combination of peptide nanostructures and 9,9-dioctylfluorene emitting polymer. Although this device shows efficiency six times lower than those build up from pure polymer, they required a lower amount of polymer in the hybrid material and exhibited biodegradability rates ~ 85% higher than architectures exclusively based on pristine polymer. Integration of peptide nanostructures with organic electronic devices represent a milestone on developing biodegradable materials for use in devices with high demand in our society, resulting in reduced environmental impact.
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VIEIRA, LUDMILA C. "Aplicação de macrófitas como biossorventes no tratamento de rejeitos radioativos líquidos." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26939.
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O rejeito radioativo como qualquer outro tipo de resíduo, precisa receber tratamento adequado. É necessário considerar suas características físico-químicas e radiológicas para a escolha da ação apropriada para o tratamento e a deposição final do rejeito. Muitas técnicas de tratamento utilizadas hoje são economicamente dispendiosas, inviabilizando muitas vezes o seu uso e impulsionando o estudo de outras técnicas de tratamento. Uma dessas técnicas é a biossorção, que demonstra alto potencial quando aplicada a rejeitos radioativos. Essa técnica utiliza materiais de origem biológica para a remoção de metais. Dos potenciais biossorventes encontrados, as macrófitas aquáticas apresentam-se vantajosas e possibilitam a remoção do urânio presente no rejeito radioativo líquido a baixo custo. O objetivo deste estudo foi avaliar a capacidade de biossorção das macrófitas aquáticas Pistia stratiotes, Limnobium laevigatum, Lemna sp e Azolla sp no tratamento dos rejeitos radioativos líquidos. Este trabalho foi dividido em duas etapas, uma de caracterização e preparação e outra de ensaios de biossorção, realizados com soluções de urânio e com rejeito real. As biomassas foram testadas na sua forma bruta e os ensaios de biossorção foram realizados em frascos de polipropileno contendo 10 mL de solução de urânio ou 10 mL de rejeito radioativo e 0,20 g de biomassa. O comportamento das biomassas foi avaliado por meio da cinética de sorção e modelos de isotermas. As maiores capacidades de sorção foram observadas com as macrófitas Lemna sp com 162,1 mg/g e para a Azolla sp com 161,8 mg/g. Os tempos de equilíbrio obtidos foram de 1 hora para a Lemna sp, e de 30 minutos para a Azolla sp. Com o rejeito real, a macrófita Azolla sp apresentou uma capacidade de sorção de 2,6 mg/g. Estes resultados sugerem que a Azolla sp possui maior capacidade de biossorção, sendo a mais indicada para estudos mais detalhados de tratamento de rejeitos radioativos líquidos.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
48
Candel, Busquets Inmaculada. "Functional silica materials for controlled release, sensing and elimination of target molecules." Doctoral thesis, Universitat Politècnica de València, 2014. http://hdl.handle.net/10251/39101.
Full textAbstract:
La presente tesis doctoral titulada “Materiales de sílice funcionales para la
liberación controlada, detección y eliminación de moléculas de interés” se centra
en el diseño y desarrollo de materiales híbridos orgánico-inorgánicos mediante la
aplicación de los conceptos de Química Supramolecular. Durante el desarrollo de
la presente tesis doctoral se han preparado y caracterizado diferentes materiales
de base silícea para distintas aplicaciones.
La primera parte de la tesis se centra en el desarrollo de materiales de base silícea
capaces de variar su comportamiento fluorescente en función de la presencia o
ausencia de un cierto analito en el medio. Estos materiales emplean como soporte
nanopartículas de sílice que se funcionalizan superficialmente con dos unidades
diferentes, una coordinante y una indicadora (un fluoróforo). La interacción del
analito de interés (en nuestro caso aniones) con la unidad coordinante modificará
las propiedades emisivas del fluoróforo. Así, se han preparado dos materiales en
los cuales el grupo fluorescente es rodamina mientras que el grupo coordinante
es un imidazolato o una sal de guanidinio respectivamente. Una vez
caracterizados ambos materiales se estudió su comportamiento frente a
diferentes especies aniónicas a diferentes concentraciones resultando selectivos a
la presencia de benzoato (el material funcionalizado con imidazolatos),
dihidrógeno fosfato e hidrógeno sulfato (el material funcionalizado con sales de
guanidinio).
El tercer capítulo de la tesis se centra en la aplicación de materiales híbridos
orgánico-inorgánicos para la detección y eliminación de especies altamente
tóxicas como son los agentes neurotóxicos. Estos son compuestos
organofosforados capaces de causar graves lesiones en el sistema nervioso
central. En una primera aproximación se emplea el concepto de puerta molecular
para la detección de agentes neurotóxicos. Para ello, se utiliza como soporte
inorgánico un material mesoporoso de sílice (MCM-41) cuyos poros se cargan con
un colorante que actúa de indicador mientras que la superficie externa del mismo se funcionaliza con una molécula capaz de reaccionar con dichos agentes
neurotóxicos. Dicha molécula es capaz de interaccionar entre sí (mediante enlaces
de hidrógeno) formando una red que mantiene bloqueada la salida de los poros.
En presencia de DCP (dietilclorofosfato, un simulante de agente neurotóxico), y
después de que este reaccione con dicha molécula, se produce una reorganización
espacial que permite la liberación del colorante. De este modo, la presencia de los
agentes neurotóxicos está señalizada mediante un cambio de color. En una
segunda aproximación se aborda el uso de soportes inorgánicos de tipo MCM-41
como materiales para la eliminación de agentes neurotóxicos. Para ello se
modificaron químicamente las superficies de estos materiales silíceos mediante
tratamiento con distintas bases. Como consecuencia de este tratamiento básico
los silanoles de la superficie se desprotonan dando lugar a los correspondientes
silanolatos (nucleófilos fuertes). Estos silanolatos son capaces de reaccionar con
los agentes neurotóxicos descomponiéndolos y favoreciendo su eliminación de un
medio contaminado.
Por último, se estudia la aplicación de materiales híbridos orgánico-inorgánicos
funcionalizados con puertas moleculares en aplicaciones de liberación controlada,
concretamente, en liberación controlada intracelular de fármacos de interés. El
material híbrido consta de un soporte de sílice mesoporosa cuyos poros se cargan
con un compuesto citotóxico (camptotecina) y su superficie externa se
funcionaliza con una gluconamida. La presencia de una monocapa densa de
gluconamidas por el exterior del material inhibe la liberación del compuesto
citotóxico. Al añadir enzimas con capacidad para hidrolizar enlaces amida
(amidasa y pronasa) se produce la liberación de la camptotecina. El correcto
funcionamiento del material se comprobó in vitro e in vivo (en células HeLa).Candel Busquets, I. (2014). Functional silica materials for controlled release, sensing and elimination of target molecules [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39101
TESIS
49
Bailly, Loïc. "Cellules photovoltaïques organiques souples à grande surface." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-01005188.
Full textAbstract:
Afin d obtenir une approche où l aspect industriel du projet est soutenu par les connaissances académiques et les capacités analytiques du monde de la recherche, ce travail portant sur les cellules photovoltaïques organiques souples grande surface commence par décrire l énergie photovoltaïque dans son ensemble. Les tenants et aboutissants de son développement sont détaillés, ainsi que ses filières technologiques. Les semi-conducteurs organiques, les mécanismes physiques mis en jeu dans la production d électricité d origine photovoltaïque et les grandeurs électriques associées aux cellules photovoltaïques organiques ainsi que les différentes structures de celles-ci sont ensuite présentés. Les dispositifs réalisés dans le cadre de ce travail sur les cellules photovoltaïques organiques sont présentés. Les différentes techniques de dépôt de couches minces, aussi bien celles permettant la production en masse que celles permettant la production à plus petite échelle sont présentées. Cette présentation s accompagne d une recherche qui se veut exhaustive des publications relatant l utilisation des ces techniques d impression afin de créer des dispositifs photovoltaïques organiques. Une comparaison de ces différentes techniques est menée afin de déterminer les modes de production pertinents. Une étude bibliographique complète menée sur les cellules grande surface est présentée. Les cellules et modules réalisés grâce au procédé pilote d enduction par héliogravure sont ensuite présentés. Le travail réalisé sur un autre procédé, le doctor blade , est ensuite exposé. Enfin, la problématique du séchage et du recuit des couches minces déposées en continu est posée, et le traitement micro-onde proposé comme solution.
50
Tinelli, Pascal. "Etude et realisation d'un detecteur microdosimetrique destine a la radioprotection." Toulouse 3, 1986. http://www.theses.fr/1986TOU30154.
Full textAbstract:
Cette etude a ete consacree a la realisation d'un compteur proportionnel au tissu biologique. Ce detecteur sensible aux neutrons et aux gamma, est destine a mesurer l'equivalent de dose dans le cadre de la radioprotection. L'analyse microdosimetrique des impulsions permet de calculer la dose absorbee et le facteur de qualite, en faisant eventuellement la discrimination entre les deux types de particules