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Lee, Kwan-Ho. "Development of four novel UWB antennas assisted by FDTD method." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1103659688.
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Wisung, Grete. "Method evaluation : Electrical surface resistance measurements on coated conductive textiles." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-14769.
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This thesis has evaluated how electrical surface resistance can be measured on conductive coated textiles using two different probes. The electrical surface resistance is a measurement for how difficult it is for current to flow through a material. For textiles, the surface resistance can be measured using four metallic plates, that measure the difference between current supply and voltage drop, this method is called a linear four-point probe. There is no standard method for measuring the electrical surface resistance on conductive textiles. Therefore, it is not possible to compare textiles made by different producers. It is also not possible to decide what the true resistance is and as conductive textiles are becoming more popular to use, this has started to become a problem in the industry. Two probes with electrodes of different dimensions were used to evaluate how different electrodes would affect the measured resistance. Measurements were conducted on conductive coated textiles with varying parameters, like coating thickness, sample size and textile construction, to show how the electrical resistance properties differ depending on what probe was used. It was found that in contrast to other research on conductive textiles and collinear four-point probes, the probes used in this study could detect electrical anisotropic properties. The resistance was different depending on what angle it was measured in. This was found for both a thicker coating and a thinner one. It was also found that the probes could detect a correlation between the angular resistance and the textile construction used. By measuring the resistance on small samples with the same dimension as the probes electrodes, the resistance was increased compared to when measurements were conducted on samples with dimensions significantly larger than the probes. Furthermore, the results showed that increasing the distance between the inner electrodes of the probe decreased the measured resistance for both large and small samples. Additionally, it was found that by increasing the width of the outer electrodes the resistance was decreased, an increase in outer electrode width also made it easier to detect electrical anisotropic properties.
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Hrabovský, Miloš. "Příprava a použití exfoliovaných grafitových/grafenových vrstev v oblasti nanosenzoriky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231377.
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Tato diplomová práce se věnuje výrobě vrstev grafitu/grafenu a meření jejich transportních vlastností v závislosti na relativní vlhkosti. Grafenové šupinky byly nanášeny pomocí mechanického odlupování . Pro kontaktování grafenových šupinek byla využita elektronová litografie a na pozorování byly využity optická mikroskopie, mikroskopie atomárních sil a elektronová mikroskopie. V práci jsou popsány jednotlivé kroky výroby, analýzy a měření transportních vlastností nanesených grafenových šupinek.
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Sousa, Makcydra Amisterdania Costa Ferreira. "Estudo das propriedades elétricas de compósitos carbono-argila obtidos a partir da borra de petróleo pelo método de quatro pontas." Universidade Federal de Sergipe, 2010. https://ri.ufs.br/handle/riufs/3509.
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Conselho Nacional de Desenvolvimento Científico e TecnológicoThe petroleum industry produces significant amounts of residues in several of its processes, from the perforation of wells, production, storage, transport and refining, to the distribution of its derivatives. The wastewater generated in the oil extraction step is known as produced water and, when stored in flotation tanks, if generates a residue called oily sludge . In a previous report, carbon-clay composites were obtained from this oily sludge and it was found this the material shows semiconductor properties. Thus, here we aimed to further evaluate the electrical properties of the carbon-clay composites using a home-made four probe apparatus. The carbon-clay composites have been prepared using the pyrolysis conditions reported in the previous study, changing here the precursor granulometry then afterwards characterizing the samples by FTIR, XRD, Raman and SEM. The presence of clays-mineral phases as well as carbon rich phases was evidenced from FTIR spectroscopy. Raman spectra revealed the presence of graphitic crystallites in addition to a disordered carbon matrix. XRD data allowed us to properly identify the mineral phases. SEM images have shown a clear effect of the precursor granulometry on the microstructure of the final pellets. Compact pellets can be expected when using a precursor with smaller particle size. The electrical measurements were accomplished using both a current source especially built for this and alternatively a Keithey 237 electrometer coupled to the four-probe apparatus. Satisfactory current values in terms of stability and reproducibility were obtained with both sources in the range of 640 μA (minimum potential) 37 mA (maximum potential). Applying current values in this range for the carbon-clay composite samples it was possible to confirm their semiconductive properties, since conductivities were found to lie in the range ≈10-4 (Ω*cm)-1. Finally the sample compactness was found to play a significant role in the electrical conductivity since the higher conductivity values were found for more compact samples.
A indústria petrolífera produz quantidades significativas de resíduos em vários dos seus processos, desde a perfuração de poços até a distribuição de seus derivados. Nesse ambiente industrial surge a chamada água produzida, que ao ficar em tanques de flotação, gera um resíduo chamado de borra de petróleo . A partir de uma observação preliminar, realizada por Andrade et al, do compósito carbono-argila, utilizando a espectroscopia de impedância eletroquímica, foi possível identificar que o material em estudo é um semicondutor. Desta maneira, surgiu o interesse de estudar com mais profundidade as características elétricas do mesmo. O objetivo deste trabalho é realizar um estudo das propriedades elétricas do compósito, destacando seus parâmetros principais como condutividade e resistividade elétricas, pelo método de quatro pontas e caracterizar a borra de petróleo gerada no tratamento de água produzida. A borra de petróleo foi seca inicialmente por 48 horas a 110ºC, foram feitas pastilhas com material peneirado a granulometrias diferentes e depois sinterizadas sob atmosfera inerte de nitrogênio, até 800ºC com isoterma de 2h. Em seguida, foi realizada a montagem do aparato de quatro terminais utilizando eletrodos de latão e de platina, para medição de resistividade elétrica do material e a montagem de uma fonte de corrente constante. Através do espectro FTIR, observou-se banda referentes aos estiramento O-H de argilominerais; bandas de resíduos orgânicos; e banda dos componentes minerais. As análises de DRX apresentaram como constituintes a montmorilonita, quartzo, calcita e barita, bem como a cristobalita, ghelenita, anortita e magnetita. O Raman apresentou banda devido à presença de carbono grafite e banda devido à desordem na estrutura do carbono grafite. A análise por MEV apresentou em algumas amostras superfície mais compactada com a presença de grãos e aglomerados. Tanto com a fonte construída, quanto com um eletrômetro obteve-se uma estabilidade de corrente na faixa de 640μA a 37mA. Foi possível comprovar com ambas as medidas que o material em estudo é um material que apresentou um valor de condutividade na faixa da semicondução (≈10-4 Ω.cm)-1.
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Haughey, Caitlin, Lauri Mesilaakso, Erik Berner-Wik, Emma Östlund, Jonatan Ulfsparre, and Hampus Olin. "Probes for ESBL : A Method for Production of Probe Targets in Antibiotic Resistant Genes." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-323686.
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This project aimed to find a method for producing potential probe targets for identification of ESBL (Extended Spectrum Beta Lactamase) genes in bacteria. ESBLs are a type of enzymes responsible for antibiotic resistance in many bacteria. The result we developed was a semi-automated pipeline that utilises several Perl scripts to download gene sequences, identify sequence subgroups based on sequence similarity, find common target sequences among them and screen the target sequences against a background database. These target sequences should work with padlock probes and therefore had specific requirements regarding length and highest number of allowed mismatches. This report includes descriptions of the scripts and ideas for future improvements, as well as an ethical analysis about aspects relevant to research on antibiotic resistance.
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Rodríguez, Fernández Jesús. "Variación térmica de la resistividad eléctrica en nuevos materiales metálicos: compuestos de tierras raras y aleaciones amorfas." Doctoral thesis, Universidad de Cantabria, 1987. http://hdl.handle.net/10803/22695.
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En la presente memoria se describe el método para la medida de la variación térmica de la resistividad entre 10 y 300 K que hemos puesto a punto en nuestros laboratorios de la Universidad de Cantabria. Dicho método es el de cuatro puntas con corriente alterna y detección síncrona. También se analizan, mediante el método de los elementos finitos, los efectos de la geometría de la muestra y posición de los contactos en la relación entre la resistividad observada experimentalmente y la resistividad real, haciendo hincapié en el caso de muestras anisótropas. Posteriormente aplicamos esta técnica al estudio de diversas series de materiales:
1) Los compuestos RPt que cumplen la Ley de De Gennes y en los que hemos podido determinar los valores de la masa efectiva m* y de la constante de canje.
2) Los compuestos RNi2Si2 en las que se puede observar una relación entre la resistividad magnética y las estructuras magnéticas.
3) Los compuestos CeyLa1-yNixPt1-x, en las que se estudia el efecto Kondo
4) Los amorfos metálicos (Co1-x(Fe5Ni5)x)75Si15B10 en los que se observa un mínimo en la resistividad a bajas temperaturas así como variaciones en lnT, T2 y T a temperaturas bajas, intermedias y altas respectivamenteThe present report describes the method for measuring the temperature dependence of the resistivity between 10 and 300 K that we have developed in our laboratories at the University of Cantabria. This is a four-probe method using ac current and synchronous detection. Also it is analyzed, using the finite element method, the effects of the sample geometry and contacts position in the relationship between the real resistivity and resistivity observed experimentally, even in the case of anisotropic samples. Subsequently we apply this technique to the study of different family of materials: 1) RPt compounds which follow the De Gennes Law, allowing us to determine the values of the effective mass m * and exchange constant. 2) The compounds RNi2Si2 in which it is possible to establish a relationship between the magnetic resistivity and the magnetic structures. 3) The compounds CeyLa1-yNixPt1-x, in which we study the Kondo effects. 4) The amorphous Co1-x(Fe5Ni5)x)75Si15B10 metals, in which there is a minimum in the resistivity at low temperatures as well as variations in LnT, T2 and T at low, intermediate and high temperatures respectively.
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Boulerouah, Aoumeur. "Propriétés thermiques et électriques de composites à base de nanotubes de carbone et application à la détection de gaz." Phd thesis, Université du Littoral Côte d'Opale, 2011. http://tel.archives-ouvertes.fr/tel-00827011.
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Les nanomatériaux suscitent depuis quelques décennies de plus en plus d'intérêt tant sur le plan des études fondamentales que sur celui des applications. Parmi ces nouveaux matériaux, les nanotubes de carbone ont attiré beaucoup d'attention au sein de la communauté scientifique à cause de leurs propriétés physiques remarquables. Les travaux présentés dans cette thèse, concernent l'élaboration et la caractérisation de composites solides à base de nanotubes de carbone. Le choix des matériaux s'est porté sur une matrice solide à base de Bromure de Potassium (KBr) et des nanotubes de carbone mono et multifeuillets (SWNT, MWNT). L'étude de ces composites concerne deux aspects : dans un premier temps, l'effet de la charge et de la nature des nanotubes de carbone sur les propriétés électriques et thermiques ont été étudiés. L'étude des propriétés thermiques a été réalisée à l'aide d'une technique photothermique, la photoacoustique, qui présente un grand avantage pour ce type de composites. L'évolution des propriétés thermiques en fonction de la charge a montré un comportement atypique, une augmentation puis une diminution, avec un maximum autour de 2% de charge en nanotubes. Un modèle physique permettant de décrire cette évolution a été proposé. Concernant les propriétés électriques, cette étude a permis de mettre en évidence le phénomène de percolation et d'en déterminer le seuil. Dans un deuxième temps, l'étude a porté sur l'influence du gaz environnant sur les propriétés thermiques et électriques, et sur l'éventuelle utilisation de ces composites comme capteurs de gaz. La caractérisation thermique en présence d'éthanol n'a pas permis de mettre en évidence un changement notable des propriétés thermiques des composites. En revanche, la caractérisation électrique a montré une bonne réponse à ce gaz. L'évolution de la sensibilité en fonction de la charge en nanotubes dans les composites a montré une augmentation pour des charges inférieures à 4% et une stabilisation au-delà. L'influence d'autre gaz comme le dioxyde d'azote et le toluène a été aussi étudié. La réponse électrique au dioxyde d'azote a montré une forte interaction du gaz avec les composites. La réponse au toluène n'a pas montré d'influence de ce gaz sur les propriétés électriques des composites à base de SWNT, cependant, dans le cas des composites à base de MWNT, une réponse électrique comparable à celle de l'éthanol a été observée.
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Mullin, Nicholas William. "Dynamic Imaging Methods for Scanning Probe Microscopy." Thesis, University of Sheffield, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521859.
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Reiter, Fernando. "Carbon based nanomaterials as transparent conductive electrodes." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41070.
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Optically transparent carbon based nanomaterials including graphene and carbon nanotubes(CNTs) are promising candidates as transparent conductive electrodes due to their high electrical conductivity coupled with high optical transparency, can be flexed several times with minimal deterioration in their electronic properties, and do not require costly high vacuum processing conditions.
CNTs are easily solution processed through the use of surfactants sodium dodecyl sulfate(SDS) and sodium cholate(SC). Allowing CNTs to be deposited onto transparent substrates through vacuum filtration, ultrasonic spray coating, dip coating, spin coating, and inkjet printing. However, surfactants are electrically insulating, limit chemical doping, and increase optical absorption thereby decreasing overall performance of electrodes. Surfactants can be removed through nitric acid treatment and annealing in an inert environment (e.g. argon).
In this thesis, the impact of surfactant removal on electrode performance was investigated. Nitric acid treatment has been shown to p-dope CNTs and remove the surfactant SDS. However, nitric acid p-doping is naturally dedoped with exposure to air, does not completely remove the surfactant SC, and has been shown to damage CNTs by creating defect sites. Annealing at temperatures up to 1000°C is advantageous in that it removes insulating surfactants. However, annealing may also remove surface functional groups that dope CNTs. Therefore, there are competing effects when annealing CNT electrodes. The impacts on electrode performance were investigated through the use of conductive-tip atomic force microscopy, sheet resistance, and transmittance measurements.
In this thesis, the potential of graphene CNT composite electrodes as high performing transparent electrodes was investigated. As-made and annealed graphene oxide CNT composites electrodes were studied. Finally, a chemical vapor deposition grown graphene CNT composite electrode was also studied.
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Deguchi, Mikio. "Study on the insulated probe method for monitoring processing plasma." 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/149472.
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Walke, Daniel John. "New instrumentation and methods for ultrafast pump-probe spectroscopy." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/48040.
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Recent advances have led to the demonstration of trains of attosecond pulses and isolated attosecond pulses in the vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) regions of the electromagnetic spectrum in a number of laboratories. This has raised the possibility of direct time resolved measurements of correlation driven electron dynamics within molecules, with a long term aim of unprecedented control over the dynamics of matter at atomic and molecular length scales. Particular interest has arisen towards the possibility of a charge migration mechanism within molecules, in which purely electron driven processes result in the movement of charge around an excited molecule in the absence of any nuclear dynamics. However, even once these sources have been established, using them in time resolved experiments is challenging. This is due to extremely short time-scales involved, the complexity of the processes under study, and the limitations of currently available attosecond sources. In this thesis I describe the development of novel instrumentation and methods for attosecond pump – probe experiments on electron dynamics in molecules. Strategies for the experimental study of charge migration are reviewed in detail which motivates the design and implementation of a purpose built instrument combining an electron velocity map imaging (VMI) spectrometer and an ion time of flight (iTOF) spectrometer. This instrument is designed in tandem with the development and characterisation of an isolated pulse at the new photon energy of 20eV. This 20eV pulse is intrinsically synchronized with another attosecond pulse at 90eV. Together, the new instrument and light source represent a unique capability for the investigation of electron dynamics in molecules. Finally, the first experimental results are presented and perspectives for future studies using the new developments are discussed.
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Karlsson, Filip. "Unfolding probes : A novel method for biomolecular detection." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-198831.
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Unfolding probes is a novel detection method for biomolecules, involving an oligonucleotide probe that can be amplified and which thereby gives rise to a strong signal for individual probe - target interactions. The present project focuses on a variant of unfolding probes called 2-fold probes and on optimizing the detection efficiency of synthetic targets. Furthermore, proof of concept experiments were performed for the detection of Her2 mRNA in cells.
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Matía, Hernando Paloma. "Attosecond pump-probe methods for measurement of molecular hole dynamics." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/50155.
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The generation of few-cycle pulses at near-infrared wavelengths is now a robust technology, as is their application to the efficient production of high-order harmonics in the extreme ultraviolet region with temporal confinement to hundreds of attoseconds. Recent years have seen considerable efforts directed to the study of electron dynamics in complex molecules in real time, with relevance to processes such as photosynthesis and radiation damage of proteins and DNA. This work describes the development of new and unique sources suited for the study of such dynamics, together with novel instrumentation and experimental methodology. This includes a pair of synchronised attosecond pulses at different photon energies in the VUV and XUV regions, which we have generated via high harmonic generation from a few-cycle NIR source and characterised with attosecond streaking. We have also explored the possibilities of sub-cycle control of these attosecond pulses by adding a second harmonic field to the high- harmonic generation process, and simultaneously characterised this second harmonic field with a novel characterisation technique known as ARIES, capable of waveform sampling at arbitrary optical wavelengths. In parallel, we have developed a few-cycle short-wavelength IR source for a UK user facility, to take advantage of the favourable wavelength scaling of the maximum photon energy achievable via high-harmonic generation. Using a commercial optical parametric amplifier and a hollow-core fibre compression system, we have generated sub-2-cycle pulses at 1750 nm, characterised via third-harmonic autocorrelation and a novel implementation of the dispersion scan technique. We have commissioned a beamline for attosecond pump-probe studies in the gas phase, including a purpose-built dual spectrometer with capabilities for simultaneous measurement of mass spectra of ions and velocity-map imaging of electrons. We have performed initial VUV-NIR pump-probe experiments on a small organic molecule, namely isopropanol, and identified a time- dependent signature as an IR-induced coupling. Finally, we have considered perspectives for future studies in attosecond pump-probe experiments with the demonstration of a two-VUV-photon process in helium performed with a moderate energy, high repetition rate attosecond source.
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Fabris, Davide. "Ultrafast light sources and methods for attosecond pump-probe experiments." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/25283.
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In this thesis I describe the development of novel light sources to be applied in attosecond pump-probe experiments, together with new methods dedicated to their characterisation and optimisation. Femtosecond pulses are a necessary tool to enter the attosecond domain. For this reason their development is a key element to unlock more capabilities in pump-probe attosecond experiments. The dynamics of generation and compression of few-cycle femtosecond pulses has been studied in a hollow core fibre system. The carrier envelope phase stability performance under increasing input power to the fibre system has been examined systematically, showing the effects of ionisation on the carrier envelope phase stability. Two characterisation techniques have been developed to measure ultrafast femtosecond pulses. A version of the d-scan technique has been demonstrated in the single shot regime for the first time, extending the utility of this diagnostic. An all optical technique (ARIES) for the characterisation of the full waveform of a femtosecond pulse has been developed, exploiting the high harmonics generation process and the sensitivity of the cut-off emission to the instantaneous amplitude of the generating electric field. The main results of the thesis are concerned with the generation of isolated attosecond pulses in new spectral regions. Vacuum ultraviolet few-femtosecond and attosecond pulses have been generated by filtering with metallic foils the high harmonics emission driven by sub-4 fs pulses, and were characterised with the attosecond streaking technique. When using indium as spectral filter a pulse duration of 1.7±0.1 fs was measured at a photon energy of 15 eV. When using tin as spectral filter a pulse duration of 585±31 as was measured at a photon energy of 20 eV. The experimental techniques developed in this thesis allow these pulses to be generated simultaneously with a XUV pulse with a measured duration of 270±25 as. This work will open new opportunities for pump-probe experiments, for example studies of ultrafast charge migration in large molecules.
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Wilkins, Denise C. "Spectrofluorometric Probe Methods for Examining Preferential Solvation in Binary Mixtures." Thesis, University of North Texas, 1994. https://digital.library.unt.edu/ark:/67531/metadc277883/.
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Spectrofluorometric probe methods are developed and examined regarding their ability to model preferential solvation around probe molecules in binary solvents. The first method assumes that each fluorophore is solvated by only one type of solvent molecule and that each fluorophore contributes to the emission intensity. Expressions for this model are illustrated using fluorescence behavior of pyrene, benzo[e]pyrene, benzo[ghi]perylene, and coronene dissolved in binary n-heptane + 1,4-dioxane and n-heptane + tetrahydrofuran mixtures. The second method treats the solvational sphere as a binary solvent microsphere, with the fluorophore's energy in both the ground and the excited states mathematically expressed using the "nearly ideal binary solvent" (NIBS) model. Expressions derived from this model are illustrated using fluorescence behavior of 9,9'-bianthracene and 9,9*-bianthracene-10-carboxaldehyde in binary toluene + acetonitrile and dibutyl ether + acetonitrile.
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Popernack, Thomas G. Jr. "Development of a data reduction method for a high frequency angle probe." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45881.
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A data reduction method has been developed and tested for a high frequency angle probe. The angle probe is designed for unsteady aerodynamic measurements in transonic cryogenic wind tunnels. The probe measures time-resolved total pressure, static pressure, angle of attack, and yaw angle from readings of four pressure transducers. The unique feature of this probe, as compared to a conventional multi-hole directional probe, is that the four high frequency response silicon pressure transducers are mounted flush on the probe tip. The data reduction method is basically an interpolation routine of calibration curves. The calibration curves consist of experimentally determined non-dimensional flow coefficients.
Two experiments were conducted to test the probe and the data reduction method.
The first experiment tested the angle probe in a Karman vortex street shed from a cylinder.
In the second experiment, the angle probe was placed in an open air jet with an
exit Mach number of 0.42. Plots of the time-resolved measurements and the Fast
Fourier Transform analysis were made for each test.
Master of Science
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Rönnberg, Sofia. "Design Probes : A Good Method for Designing with Children." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-150461.
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Design probes are a User-centered Design method with focus on close involvement of users in design. This is done by creating a package of artefacts that participants can complete wherever and whenever the individual sees fit. Further, children are a user group that differentiate from other user groups having other needs and attributes within design. This study investigated how design probes motivate children in the design process. A focus of the study is also to compare the applicability of thematic and non-thematic design probes with children. The study was conducted with a qualitative approach where the empirical data was in the shape of four different design probes that were created and tested by students from Linköping University from the program of Design and Product Development. The tests they carried out were performed on children at the age of 10 to 13. Data analysis were made through coding and thematic analysis. The study concludes that design probes is an adequate method for designing with children. Although, there are additional challenges in terms of playfulness, motivation, language, rewards, time-sense, creativity, influences and reflection. If design probes with children are managed correctly, they will yield results of great value to design. Also, having a theme in the design probe might help to motivate children. Although, themes are no guarantee for success since it will not solve challenges that are independent of themes. Keywords: Design probe, children, designing with children, User-centered Design, motivation
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Graziani, Alberto <1980>. "Troposphere Calibration Techniques for Deep Space Probe Tracking." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/3023/.
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Ground-based Earth troposphere calibration systems play an important role in planetary exploration, especially to carry out radio science experiments aimed at the estimation of planetary gravity fields. In these experiments, the main observable is the spacecraft (S/C) range rate, measured from the Doppler shift of an electromagnetic wave transmitted from ground, received by the spacecraft and coherently retransmitted back to ground. If the solar corona and interplanetary plasma noise is already removed from Doppler data, the Earth troposphere remains one of the main error sources in tracking observables.
Current Earth media calibration systems at NASA’s Deep Space Network (DSN) stations are based upon a combination of weather data and multidirectional, dual frequency GPS measurements acquired at each station complex. In order to support Cassini’s cruise radio science experiments, a new generation of media calibration systems were developed, driven by the need to achieve the goal of an end-to-end Allan deviation of the radio link in the order of 3×〖10〗^(-15) at 1000 s integration time.
The future ESA’s Bepi Colombo mission to Mercury carries scientific instrumentation for radio science experiments (a Ka-band transponder and a three-axis accelerometer) which, in combination with the S/C telecommunication system (a X/X/Ka transponder) will provide the most advanced tracking system ever flown on an interplanetary probe. Current error budget for MORE (Mercury Orbiter Radioscience Experiment) allows the residual uncalibrated troposphere to contribute with a value of 8×〖10〗^(-15) to the two-way Allan deviation at 1000 s integration time.
The current standard ESA/ESTRACK calibration system is based on a combination of surface meteorological measurements and mathematical algorithms, capable to reconstruct the Earth troposphere path delay, leaving an uncalibrated component of about 1-2% of the total delay.
In order to satisfy the stringent MORE requirements, the short time-scale variations of the Earth troposphere water vapor content must be calibrated at ESA deep space antennas (DSA) with more precise and stable instruments (microwave radiometers). In parallel to this high performance instruments, ESA ground stations should be upgraded to media calibration systems at least capable to calibrate both troposphere path delay components (dry and wet) at sub-centimetre level, in order to reduce S/C navigation uncertainties. The natural choice is to provide a continuous troposphere calibration by processing GNSS data acquired at each complex by dual frequency receivers already installed for station location purposes.
The work presented here outlines the troposphere calibration technique to support both Deep Space probe navigation and radio science experiments. After an introduction to deep space tracking techniques, observables and error sources, in Chapter 2 the troposphere path delay is widely investigated, reporting the estimation techniques and the state of the art of the ESA and NASA troposphere calibrations. Chapter 3 deals with an analysis of the status and the performances of the NASA Advanced Media Calibration (AMC) system referred to the Cassini data analysis. Chapter 4 describes the current release of a developed GNSS software (S/W) to estimate the troposphere calibration to be used for ESA S/C navigation purposes. During the development phase of the S/W a test campaign has been undertaken in order to evaluate the S/W performances. A description of the campaign and the main results are reported in Chapter 5. Chapter 6 presents a preliminary analysis of microwave radiometers to be used to support radio science experiments. The analysis has been carried out considering radiometric measurements of the ESA/ESTEC instruments installed in Cabauw (NL) and compared with the requirements of MORE. Finally, Chapter 7 summarizes the results obtained and defines some key technical aspects to be evaluated and taken into account for the development phase of future instrumentation.
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Emmenegger, Leonidas Philip. "Kelvin Probe Electrode for Field Detection of Corrosion of Steel in Concrete." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5944.
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While the Kelvin Probe (KP) has been used in a variety of surface scanning applications, the use of the KP in reinforced concrete structures to detect corrosion has been pioneered by previous work performed at the University of South Florida. However, in that work, the scale and construction of the probes was not suited to use in the field. This is primarily attributable to the small operating disk-to-concrete gap which would make the probe unable to accommodate road conditions, such as irregularities in the grading of the road, and local pitting of the surface. Therefore, it was important to investigate whether the KP can be scaled up while still maintaining resolution and fidelity of the measurements taken. The new mobile KP prototype (MKPP) constructed in this work, has a sensing disk that is approximately 10 cm in diameter and is capable of operating up to 2 cm above the concrete surface. Testing consisted of mapping an instrumented test slab simulating a corroding concrete bridge deck, at a rate of travel of about 0.6 mph (~1 ft/s) over the slab surface. The potential map generated through use of the MKPP successfully identified the corroding spot, the location of which was verified using the traditional half-cell potential mapping method outlined in ASTM C 876-09. The MKPP mapping in these trials was approximately 10 times faster than when using the traditional method. The faster potential mapping by the MKPP, while still identifying corroding sites, should allow for more economical and less intrusive survey of the condition of bridge decks. The work set the necessary proof of concept for future demonstration of an array of such probes which would further magnify the beneficial effect.
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Martin, Edward C. "Methods of Measuring for Irrigation Scheduling - WHEN." College of Agriculture, University of Arizona (Tucson, AZ), 2014. http://hdl.handle.net/10150/333138.
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Revised; Originally published: 20096 pp.
Proper irrigation management requires that growers assess their irrigation needs by taking measurements of various physical parameters. Some use sophisticated equipment while others use tried and true common sense approaches. Whichever method used, each has merits and limitations. In developing any irrigation management strategy, two questions are common: “When do I irrigate?” and “How much do I apply?” This bulletin deals with the WHEN.
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Doores, Katie J. "Novel methods for the synthesis of glycoimmunological probes." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670149.
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March, Marisa Cristina. "Advanced statistical methods for astrophysical probes of cosmology." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9486.
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The work presented in my thesis develops advanced Bayesian statistical methods for using astrophysical data to probe our understanding of the Universe, I cover three main areas: Should we doubt the cosmological constant? While Bayesian model selection is a useful tool to discriminate between competing cosmological models, it only gives a relative rather than an absolute measure of how good a model is. Bayesian doubt introduces an unknown benchmark model against which the known models are compared, thereby obtaining an absolute measure of model performance in a Bayesian framework. I apply this new methodology to the problem of the dark energy equation of state, comparing an absolute upper bound on the Bayesian evidence for a presently unknown dark energy model against a collection of known models including a flat Lambda cold dark matter ( CDM ) scenario. I find a strong absolute upper bound to the Bayes factor between the unknown model and CDM. The posterior probability for doubt is found to be less than 13 per cent (with a 1 per cent prior doubt) while the probability for CDM rises from an initial 25 per cent to almost 70 per cent in light of the data. I conclude that CDM remains a sufficient phenomenological description of currently available observations and that there is little statistical room for model improvement Improved constraints on cosmological parameters from supernovae type Ia data: I present a new method based on a Bayesian hierarchical model to extract constraints on cosmological parameters from SNIa data obtained with the SALT-II lightcurve fitter. I demonstrate with simulated data sets that our method delivers considerably tighter statistical constraints on the cosmological parameters and that it outperforms the usual chi-square approach 2/3 of the times. As a further benefit, a full posterior probability distribution for the dispersion of the intrinsic magnitude of SNe is obtained. I apply this method to recent SNIa data and find that it improves statistical constraints on cosmological parameters from SNIa data. From the combination of SNIa, CMB and BAO data I obtain Ωm = 0:28 ± 0:02; ΩΛ = 0:73 ± 0:01 (assuming w = -1) and Ωm = 0:28 ± 0:01, w = -0:90 ± 0:05 (assuming flatness; statistical uncertainties only). I constrain the intrinsic dispersion of the B-band magnitude of the SNIa population, obtaining σ int μ = 0:13 ± 0:01[mag]. Robustness to systematics for future dark energy probes: I extend the Figure of Merit formalism usually adopted to quantify the statistical performance of future dark energy probes to assess the robustness of a future mission to plausible systematic bias. I introduce a new robustness Figure of Merit which can be computed in the Fisher Matrix formalism given arbitrary systematic biases in the observable quantities. I argue that robustness to systematics is an important new quantity that should be taken into account when optimizing future surveys. I illustrate our formalism with toy examples, and apply it to future type Ia supernova (SNIa) and baryonic acoustic oscillation (BAO) surveys. For the simplified systematic biases that I consider, I find that SNIa are a somewhat more robust probe of dark energy parameters than the BAO. I trace this back to a geometrical alignment of systematic bias direction with statistical degeneracy directions in the dark energy parameter space.
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Schöldström, Degenne Jacob. "Development of a new quantitative PCR analysis method for HIV-1." Thesis, KTH, Proteinvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299883.
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På grund av planerat tillverkningsstopp av instrumenten som används idag på Octapharma AB, så syftar detta projekt till nyutvecklingen av en kvantitativ PCR analysmetod för detektion av HIV-1 i human blodplasma, genom TaqMankemi. Projektet inkluderade design, testning och utvärdering av olika set av primer och probe sekvenser. För att säkerställa specificiteten hos metoden designades primrarna och proberna för att vara komplementära till olika konservativa regioner av HIV-1:s genom. Primer och probe set:en (P/P) testades både individuellt och kombinerat i spädningsserier och genotypspaneler. Analyserna visade att det inte fanns någon korrelation mellan felmatchning av P/P och referenssekvenser hos subtyper, och detektionsnivå. När P/P testades i kombination hittades falsk-positiva signaler i negativa kontroller (4 falsk-positiva signaler; n= 106). Detta åtgärdades genom att utesluta specifika prober(0 falsk-positiva signaler; n= 152)(p = 0,030, Fisher’s exact test). Kombinationen av primer och prober, med någraprober uteslutna, hade en högre detektionsnivå för HIV-1 subtyper än de individuella set:en (29 positiva prover vs 23.5; n= 64), och lyckadesäven detektera åtminstone ett positivt prov hos varje subtyp A, B, C, D, AE, F, G och H. Avsaknaden av korrelation mellan felmatchning av P/P och detektionsnivå, visar på att orsaken av den suboptimala detektionsnivån av subtyper var inte på grund av antalet felmatchningar mellan primer och probe set:en till målsekvenserna. Den högre specificiteten vid kombination av P/P indikerar även att primrar och prober som riktar in sig på olika regioner avHIV-1 genomet ytterligare ökar specificiteten och detektionsnivån hos metoden.As a result of future instrument discontinuation by Octapharma AB’s manufacturers, this project sought to develop a new quantitative PCR analysis method for the detection of HIV-1 in human blood plasma using TaqMan chemistry. The project included the design, testing and statistical analysis of different sets of novel primer and probe sequences. To ensure specificity, the primer and probe sequences were designed to target conserved regions of the HIV-1 genome. The primer and probe sets were tested both individually and in combination in dilution series and genotype tests. Linear regression analyses showed no correlation between mismatches between the primer and probe sets and the subtype reference sequences tested, and detection rate. When the primer and probe setswere tested in combination, false positive signals were obtained in negative control samples (4 false positive signals; n= 106). However, this obstacle was overcome by the omission of certain probes, resulting in no false positive signals (0 false positive signals; n= 152)(p = 0.030, Fisher’s exact test).The combination of primer and probe sets, with certain probes omitted, had an increased HIV-1 subtype detection rate compared to the individual P/P (29 positive samples detected versus 23.5; n= 64), and were also able to detect at least one positive sample from each of the HIV-1 subtypes A, B, C, D, AE, F, G, and H. The absence of correlation between primer and probe set mismatch and detection rate, suggests that the cause of the suboptimal detection rate of the subtypes was not the result of primer and probe set mismatch to the target sequences. The increased subtype detection rate upon combining the P/P also indicates that targeting different region of the HIV-1 genome further improves the detection rate and specificity of the method.
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Hevekerl, Heike. "Fluorescence-based methods to probe long-lived transient states for biomolecular studies." Doctoral thesis, KTH, Experimentell biomolekylär fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-144063.
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Fluorescence spectroscopy and imaging are wide-spread tools in life science. Themain read-out parameters are still fluorescence intensity and wavelength, but given thebenefits of multi-parameter characterization there are also good reasons to consideradditional fluorescence-based read-out parameters. A major focus of this thesis is toextend the use of transient, non-fluorescent states as additional parameters forbiomolecular studies. To-date, such states (including mainly triplet states, isomerizedstates and photo-ionized states) have been exploited to a very limited extent for thispurpose. Their use has been limited because they show very weak, or no luminescence atall, and absorption measurements require relatively complex instrumentation which aretypically not applicable for studies under biologically relevant conditions. Moreover, thelong lifetime of these transient states make any readout signal very sensitive to changes inthe micro-environment, e.g. presence of small amounts of quenchers, like oxygen. Thosetransient states can be accessed by fluorescence correlation spectroscopy (FCS) and thenewly developed transient state (TRAST) monitoring technique. In this thesis, FCS andTRAST have been applied to demonstrate the use of transient state monitoring forbiomolecular studies. In Paper I, we demonstrated that due to the low brightness requirements ofTRAST, also autofluorescent molecules like tryptophan can be studied, making externallabeling of molecules redundant. The photo-physical transient states of tryptophan andtryptophan-containing proteins could be analyzed and were found to provide informationabout protein conformational states and about the influence of pH and buffers on singletryptophan molecules. In Paper II investigations of the transient states of theoligothiophene p-FTAA with FCS as well as with dynamic light scattering andspectrofluorimetry revealed a pH dependent aggregation behavior and a very efficientfluorescence quenching by oxygen could be identified and analyzed. In Paper III, FCSand TRAST were used to monitor the isomerization kinetics of Merocyanine 540incorporated in lipid membranes. Because isomerization of cyanine dyes strongly dependson the viscosity of the local environment, the isomerization kinetics could be used tocharacterize membrane fluidity in artificial lipid vesicles and in cellular membranes. InPaper IV, a new approach was developed, based on a combination of TRAST and FCS todetermine the stoichiometry of a fluorescently labeled sample. Finally, in Paper V, FCSand TRAST were employed to demonstrate that triplet states of fluorophores can provide auseful readout for Förster Resonance Energy Transfer (FRET) reflecting intra- orivintermolecular distances between two fluorophores. The sensitivity of the triplet statemade it possible to monitor distances larger than 10 nm, which is often stated as the upperlimit of FRET interactions. Taken together, the studies presented in this thesis show that there is a wealth ofinformation that can be revealed by studying long-lived transient states. Both FCS andTRAST combine a sensitive readout via the fluorescence signal with the sensitivity of thelong-lived transient states monitored via the fluorescence changes. It can therefore bepredicted that these approaches will find additional applications in the future.QC 20140408
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Hua, Yueming. "Materials and methods for nanolithography using scanning thermal cantilever probes." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22536.
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Thesis (Ph. D.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2008.Committee Chair: Henderson, Clifford; Committee Member: Hess, Dennis; Committee Member: King, William; Committee Member: Lu, Hang; Committee Member: Tolbert, Laren.
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Claesson, Cim. "Is Multiplex Ligation-dependent Probe Amplification a good method for screening formalin fixed paraffin embedded neuroblastoma tumors?" Thesis, Högskolan i Skövde, Institutionen för vård och natur, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-5442.
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Neuroblastoma is one of the most enigmatic solid tumors for scientists and pediatric oncologists. Neuroblastoma is primary a childhood form of cancer, consisting of neuroectodermal cells that originate from the neural crest and is destined for the adrenal medulla and sympathetic nervous system. The Neuroblastoma group at The University of Gothenburg received formalin-fixed paraffin-embedded tumor samples from Vietnam and this project was to examine if the quality of the DNA from, is good enough to run comparative genome hybridization array experiment on by using a cheaper technique Multiplex Ligation-dependent Probe Amplification technique. Multiplex Ligation-dependent Probe Amplification (MRC Holland) is a multiplex PCR method that can detect abnormalities such as deletions and amplifications. By using probes consisting of one short synthetic arm with a PCR primer sequence Y at the 3´end, and one long probe with a stuffer sequence, and a PCR primer sequence X at the 5´end that can hybridize and ligate. If these probes ligate it is possible to amplify them by PCR just using specific primers for the X and Y sequences. The resulting amplification products can then be analyzed bycapillary electrophoresis. These patient that the DNA was derived from had all stage 4 neuroblastoma, and that is why they all present many aberrations. Among the fascinating data from this experiment, there are many patients with both 11q deletions and has an extreme amplification of MYCN. In Sweden only a few cases has been discovered. In this material even though all patients are stage 4 patients, 16 have this combination.
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Rao, Arun J. "Analog Front-End Design Using the gm/ID Method for a Pulse-Based Plasma Impedance Probe System." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/675.
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The Plasma Impedance Probe (PIP) is an electronic instrument that measures the impedance of a dipole antenna immersed in a plasma environment. Measurements made by the PIP provide valuable information regarding the plasma environment. Knowledge of ionospheric plasma density and density disturbances is required to understand radio frequency communication with satellites. The impedance curve provides us with significant plasma characteristics such as the electron-neutral collision frequency and plasma electron density.
The work proposed here is a transistor-level implementation of the analog front-end, the non-inverting amplifier that is used to drive the antenna. The antenna immersed in plasma is excited with a sinusoidal/pulse stimulus and the output from the non-inverting configuration is fed into the difference amplifier. In the difference amplifier the output signal from the non- inverting amplifier is subtracted from the original stimulus and then fed into a high-speed pipeline data converter. The entire analog and mixed signal components are integrated on a single chip. The obvious advantages with this design are that it eliminates several sources of analog signal processing errors, thereby improving stability. A Fast Fourier Transform (FFT) is then applied on the sampled input stimulus as well as the processed signal. The input voltage FFT is then divided by the current FFT to obtain the antenna impedance. The FFT method helps in reducing transient errors and improves noise immunity of the system. The antenna impedance span curves over the frequency range from 100 kHz to 20MHz.
The approach for the tranistor-level design is implementing short-channel design tech- niques using the gm/ID method. This is the primary focus of the thesis where the emphasis has been on using a simple and intuitive method to design the front-end amplifier in the TSMC .35 um technology. The design specifications for this amplifier are derived from the system-level simulations. The transition from a Printed Circuit Board (PCB)-based design to System on Chip (SOC) implementation is explored. This makes the design components highly specific to the application.
The following are the design approaches used for the analog front-end design.
* A detailed study of the various factors affecting the PIP instrument measurement capabilities from the previous works.
* System-level simulation of the the entire PIP system to completely characterize the analog front-end.
* Exploration of the possible design topologies for the transistor-level implementation.
* A novel method of analog amplifier design using the gm/ID methodology.
Miniaturization of the instrument and using a pulse-based measurement scheme also offer an immediate benefit to sounding rocket missions. The reduction of power, mass, and volume will enable the instrument to be flown on many more sounding rockets than at present. The faster measurement is especially valuable since the ionospheric plasma changes in character most rapidly with altitude.
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Rothe, Jessica. "Establishment of a Y-chromosome specific extraction method for the separation of Y-chromosomal haplotypes from male DNA mixtures." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2014. http://dx.doi.org/10.18452/16995.
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Die Haplotypspezifische Extraktion (HSE) bietet für die Analyse von männlichen Mischprofilen einen neuen und direkteren Lösungsansatz, in dem die haploiden Y-chromosomalen DNS-Komponenten der einzelnen Individuen bereits vor der Analyse der individual spezifischen Marker separiert werden können und dadurch eine wirkliche physische Trennung erreicht wird. Die HSE verwendet Y-chromosomalen SNPs für die Erstellung allelspezifische Extraktionssonden, die nun gezielt nur die Marker der extrahierten DNS Komponente bzw. einer Person separieren sollen. Dabei werden im Hybridisationsschritt der HSE selektive nur komplett hybridisierte Sonden durch eine Polymerase verlängert. Während der Elongation erfolgt eine Biotinylierung des neu entstehenden Stranges, welcher dann selektiv durch Streptavidin markierte Eisenkügelchen extrahiert werden kann. Erste Durchführungen einer HSE zeigten nur eine sehr schwache bis keine Anreicherung. Während der Optimierung verschiedener Parameter wurde die Schlüsselstellung des Sondendesigns in der HSE-Technik deutlich. Die Ergebnisse zeigten, dass die neu entwickelten Sonden den Trennungserfolg der Mischprobe enorm verbessern und in einigen Fällen sogar zum Ausschluss des konkurrierenden Allels führten. Ein Vergleich der HSE Ergebnisse mit den simulierten Sondenparametern der getesteten Sonden ergab, dass der Extraktionserfolg der Sonde maßgeblich durch das Zusammenspiel von Sondenlänge und GC-Gehalt bestimmt wird. Durch dieses neu gewonnene Verständnis über den Einfluss der einzelnen Sondenparameter auf den Trennungserfolg der Mischprobe, können für künftige HSE Anwendungen Sonden effizienter erstellt und deren Wirksamkeit vorhergesagt werden. Zusätzlich konnte das neu entwickelte Vorhersage-Model der Sondenspezifität auch für weitere Extraktionsorte außerhalb des Y-Chromosoms bestätigt werden. Weiterhin konnte durch die Kombination verschiedener Sonden in einer Multiplex HSE mehrerer Y-chromosomaler Marker gleichzeitig getrennt.Haplotype-specific extraction (HSE) allows the separation of diploid samples in their haploid components and offers in forensic a new straight forward method to separate Y-chromosomal mixed profiles, consisting of haplotype markers like short tandem repeats (STRs). The advantage of the HSE approach in mixture analysis is the real physical separation of the individual DNA components before the amplification of the STR markers. In order to use the HSE technique for the separation of male DNA mixtures, Y-chromosomal extraction probes were designed to single nucleotide polymorphisms (SNPs), which have been specific for one contributor of the male DNA mixtures. During extraction only complete matched probes are extended by a polymerase which results in the incorporation of biotinylated nucleotides. The synthesized and biotin labeled strand is separated by streptavidin coated magnetic beads. Finally, samples were analyzed by PCR coupled capillary electrophoresis for the detection of the extracted STR markers. First tests of a Y-chromosomal specific extraction showed only little till no enrichment of the targeted alleles. Therefore optimization tests of different parameters were carried out, which revealed the probe design as the key factor of successful HSE. A comparison between simulated probe parameters and their extraction success in HSE showed that the HSE probe efficiency mainly depends of the relation of probe length and GC-contents. Because of the new gained knowledge about the influence of the probe-design on the separation success, probes for future HSE application can be developed faster and cost-effective. The new prediction model for probe-specificity was also successful tested for the extraction of other genome-loci. Furthermore, a multiplex HSE approach was used to separate several STR markers simultaneously in one extraction reaction and therefore achieved the separation of one contributor Y-chromosomal haplotype.
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Samuelsson, Jonas. "A study into relative navigation methods for automatic probe and drogue air-to-air refuelling." Thesis, Luleå tekniska universitet, Rymdteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-81004.
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As the aerospace industry moves into more automatic systems and fully automatic systems the need for automatic air to air refuelling is becoming essential to create an optimal aircraft system. It is not only needed for UAVs but also for piloted aircraft. For the aircraft to connect with the hose is a difficult procedure where a lot of things can go wrong. Creating an automatic system will remove any human error out of the procedure to create a more efficient refuelling procedure. This study is taking a look at relative navigation methods to connect the receiver aircraft with the hose in a probe and drogue refuelling system which can be used for an automatic aircraft system for refuelling. To investigate different relative navigation methods a simulation environment was built using the relative position between each part of the system, the tanker, the hose, the drogue and the receiver. The system environment effects are also implemented to create an accurate environment that includes turbulence, wake effects, wind and bow wave effects. The complexity of each part differs from each other. The two aircraft, tanker and receiver, are modelled in 1 and 3 degrees of freedom where the hose and drogue is modelled in 5 degrees of freedom to simulate the procedure. Using this simulation environment two different methods were tested, a straight on approach where the probe of aircraft aimed to always be aligned with the drogue and an offset approach where the receiver aimed to try to predict the movement of the drogue. The findings from the simulation showed that analysing the bow wave effect on the drogue to then predict its movement by approaching with an offset was the most optimal approach. It allowed the receiver to do fewer movements during critical parts of the refuelling procedure and also were able to successfully dock during turbulent environment I can conclude that using relative navigation that using a probe and drogue air to air refuelling an automatic system should be able to work. The simulation can be expanded upon to create a more realistic environment that can give a more accurate representation of the real world dynamics. The aerodynamics of the aircraft need to be expanded upon and the aerodynamics of the disturbances can be more accurately implemented.
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Xie, Tuqiang. "Development of an opto-fluidic probe for on-line noncontact dimensional inspection and tool condition monitoring in a hazardous manufacturing environment." Thesis, Brunel University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324552.
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Rahmani, Mahmood. "Path Inference of Sparse GPS Probes for Urban Networks : Methods and Applications." Licentiate thesis, KTH, Trafik och logistik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104524.
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The application of GPS probes in traffic management is growing rapidly as the required data collection infrastructure is increasingly in place in urban areas with significant number of mobile sensors moving around covering expansive areas of the road network. Most travelers carry with them at least one device with a built-in GPS receiver. Furthermore, vehicles are becoming more and more location aware. Currently, systems that collect floating car data are designed to transmit the data in a limited form and relatively infrequently due to the cost of data transmission. That means the reported locations of vehicles are far apart in time and space. In order to extract traffic information from the data, it first needs to be matched to the underlying digital road network. Matching such sparse data to the network, especially in dense urban, area is challenging. This thesis introduces a map-matching and path inference algorithm for sparse GPS probes in urban networks. The method is utilized in a case study in Stockholm and showed robustness and high accuracy compared to a number of other methods in the literature. The method is used to process floating car data from 1500 taxis in Stockholm City. The taxi data had been ignored because of its low frequency and minimal information. The proposed method showed that the data can be processed and transformed into information that is suitable for traffic studies. The thesis implemented the main components of an experimental ITS laboratory, called iMobility Lab. It is designed to explore GPS and other emerging traffic and traffic-related data for traffic monitoring and control.QC 20121107
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De, Leon Ricardo 1957. "Use of gene probes and an amplification method for the detection of rotaviruses in water." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/191152.
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Rotaviruses are one of the most significant causes of diarrheal disease in the world. Their presence in groundwater and drinking water supplies constitutes a health risk to the population. The study of rotaviruses in the environment has been hampered by the lack of accessible and consistent detection methodologies. Gene probes and other molecular techniques are a novel approach for the detection of these viruses in water. The feasibility of these new techniques for the detection and study of rotaviruses in the environment has been assessed using the simian SA-11 and the culturable human Wa rotavirus strains as models. Two general approaches have been undertaken consisting of hybridization of probes with genomic RNA and hybridization with mRNA produced by the virion-incorporated transcriptase. Hybridization of gene probes with genomic dsRNA of rotaviruses in environmental concentrates resulted in the detection of 10 4 immunofoci of Wa rotavirus. In vitro transcription serves as an amplification method with sensitivity 100- to 1000-fold greater than when probing for genomic RNA. The sensitivity obtained in Wa-seeded distilled water and environmental concentrates after in vitro transcription is 2 and 20 immunofoci, respectively. Proteins in environmental concentrates decrease the efficiency of probe hybridization by 10-100 fold. Also, transcriptase-inhibiting factors found in environmental samples decrease the production of mRNA. Both proteins and transcriptase-inhibiting factors can be reduced significantly with Sephadex G-200 columns. Passage of environmental concentrate through Sephadex G-200 spun columns, followed by in vitro transcription, was used to detect rotaviruses in environmental samples. Rotaviruses were detected by this combination of techniques in eight of 20 sewage samples, one of 16 tap water samples, five of 32 ground water samples, and two of nine surface water samples. Only one of 17 samples which tested positive with Wa cDNA 4 was positive for non-specific probe binding. The probing of rotavirus mRNA, amplified by the virion-incorporated transcriptase, is a practical and feasible method for monitoring these viruses in the environment.
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Jaber, Wassim. "Phonon heat conduction probed by means of an electro-thermal method involving deposited micro and nanowires." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI109/document.
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The context of this PhD is the reduction of sizes involved in material development and the confinement of heat in modern devices, which are known to lead to the apparition of hot spots. The goal is to investigate heat conduction from micro- to nanoscale wide Joule-heated wires standing on flat layered materials. A particular focus is given to the analysis of phonon heat dissipation when departing from the well-known Fourier diffusive conduction and entering the ballistic regime. The manuscript starts with a summary of the main observed effects on the effective thermal conductivity in nanoscale materials, especially in light of the values of thermallyaveraged phonon mean free paths and the associated Knudsen number. Then the advantages and drawbacks of various measurement techniques are discussed. The analysis of the experimental configuration requires 2D analytical and 3D finite-element method based numerical studies of diffusive heat conduction from a finite source into a medium. Limitations of the 3! method due to wire length, substrate geometry and thin oxide layers are highlighted. The electro-thermal setup developed and the procedure used to deposit the devices on top of the samples are then detailed. A set of well-known materials with mean free path ranging from few nanometers to hundreds of nanometers is characterized with microwires. The thermal conduction properties of multilayer materials are investigated. Heat dissipation from finite sources on top of silicon substrates is then measured as a function of temperature. The mean free path is known to become large when temperature decreases. As a result, this configuration provides clues for understanding heat conduction from ballistic sources. The observed behavior is very different from the one predicted by Fourier’s law and shows a strong reduction of the dissipation. It is found that the results are comparable to earlier measurements involving ridges. They are analyzed with various levels of approximations of predictions using the Boltzmann transport equation. The results obtained may be useful in many fields, in particular for electronics and thermoelectric designsLe contexte de ce doctorat est la réduction des tailles impliquées dans le développement des matériaux et le confinement de la chaleur dans les dispositifs modernes, qui sont connus pour conduire à l'apparition de points chauds. L'objectif est d'étudier la conduction de la chaleur à partir de fils chauffés par Joule à l'échelle nanométrique et à l'échelle nanométrique, reposant sur des matériaux à couches planes. Une attention particulière est accordée à l'analyse de la dissipation thermique des phonons en partant de la conduction de Fourier bien connue et en entrant dans le régime balistique. Le manuscrit commence par un résumé des principaux effets observés sur la conductivité thermique effective dans les matériaux à l'échelle nanométrique, en particulier à la lumière des valeurs des voies libres moyennes des phonons et du nombre de Knudsen associé. Ensuite, les avantages et les inconvénients des différentes techniques de mesure sont discutés. L'analyse de la configuration expérimentale nécessite des études numériques 2D basées sur la méthode des éléments finis et des éléments finis de la conduction de chaleur par diffusion à partir d'une source finie dans un milieu. Limitations du 3! méthode en raison de la longueur du fil, de la géométrie du substrat et des couches minces d'oxyde sont mises en évidence. La configuration électro-thermique développée et la procédure utilisée pour déposer les dispositifs sur les échantillons sont ensuite détaillées. Un ensemble de matériaux bien connus avec un chemin libre moyen allant de quelques nanomètres à des centaines de nanomètres est caractérisé par des microfils. Les propriétés de conduction thermique des matériaux multicouches sont étudiées. La dissipation thermique des sources finies sur les substrats de silicium est ensuite mesurée en fonction de la température. Le libre parcours moyen est connu pour devenir important lorsque la température diminue. En conséquence, cette configuration fournit des indices pour comprendre la conduction de la chaleur à partir de sources balistiques. Le comportement observé est très différent de celui prédit par la loi de Fourier et montre une forte réduction de la dissipation. On trouve que les résultats sont comparables à des mesures antérieures impliquant des crêtes. Ils sont analysés avec différents niveaux d'approximations de prédictions en utilisant l'équation de transport de Boltzmann. Les résultats obtenus peuvent être utiles dans de nombreux domaines, en particulier pour les conceptions électroniques et thermoélectriques
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Strauß, Sebastian [Verfasser], and Veit [Akademischer Betreuer] Hornung. "Advanced labeling methods and probe design for DNA-based super-resolution microscopy / Sebastian Strauß ; Betreuer: Veit Hornung." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2021. http://d-nb.info/1241963703/34.
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Kajita, Shin, Noriyasu Ohno, Shuichi Takamura, and Tomohide Nakano. "Comparison of He I line intensity ratio method and electrostatic probe for electron density and temperature measurements in NAGDIS-II." American Institute of Physics, 2005. http://hdl.handle.net/2237/7050.
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Setu, Dambhare. "Development of a specific and sensitive method for detection and quantification of Ustilago nuda by qPCR." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-20243.
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Loose smut of barley, caused by fungal pathogen Ustilago nuda is one of the major concerns throughout the globe for barley producers. The infection takes place without exhibiting any obvious symptoms and an infected seed lot can only be identified at the heading stage when the fungal teliospores emerge at the place of crop. The percentage losses on yield are directly proportional to the occurrence of infection. Currently available detection methods include seed health testing protocols which are time-consuming and cumbersome. With the globalization of the international market and increased crop demand, development of rapid disease screening methodologies has become an essential focus in the field of plant pathology. The present study sought to develop a rapid probe-based detection method for screening of U. nuda with real-time qPCR. Two U. nuda specific primer pairs were compared using standard PCR alongside optimization of real-time qPCR assay. The advantage of high fidelity DNA polymerase for amplification of U. nuda genomic DNA was recorded. U. nuda genomic DNA was amplified and cloned into a vector which was further used for generation of a quantification curve with a specific probe. The qPCR assay developed in this study was successful in the detection of as little as 43 copies of U. nuda genomic DNA. With studies involving larger sample size and field samples, this assay can be improved for enhanced sensitivity and specificity which can help in monitoring infection from DNA extractions of barley seeds and further improving the current microscopic detection methods.
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Gross, Brett Ivan. "Investigation of a method for monitoring stress changes in the burst prone seams of southwestern Virginia." Thesis, This resource online, 1988. http://scholar.lib.vt.edu/theses/available/etd-04122010-083722/.
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Mignardi, Marco. "In situ Sequencing : Methods for spatially-resolved transcriptome analysis." Doctoral thesis, Stockholms universitet, Institutionen för biokemi och biofysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-110057.
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It is well known that cells in tissues display a large heterogeneity in gene expression due to differences in cell lineage origin and variation in the local environment at different sites in the tissue, a heterogeneity that is difficult to study by analyzing bulk RNA extracts from tissue. Recently, genome-wide transcriptome analysis technologies have enabled the analysis of this variation with single-cell resolution. In order to link the heterogeneity observed at molecular level with the morphological context of tissues, new methods are needed which achieve an additional level of information, such as spatial resolution. In this thesis I describe the development and application of padlock probes and rolling circle amplification (RCA) as molecular tools for spatially-resolved transcriptome analysis. Padlock probes allow in situ detection of individual mRNA molecules with single nucleotide resolution, visualizing the molecular information directly in the cell and tissue context. Detection of clinically relevant point mutations in tumor samples is achieved by using padlock probes in situ, allowing visualization of intra-tumor heterogeneity. To resolve more complex gene expression patterns, we developed in situ sequencing of RCA products combining padlock probes and next-generation sequencing methods. We demonstrated the use of this new method by, for the first time, sequencing short stretches of transcript molecules directly in cells and tissue. By using in situ sequencing as read-out for multiplexed padlock probe assays, we measured the expression of tens of genes in hundreds of thousands of cells, including point mutations, fusions transcripts and gene expression level. These molecular tools can complement genome-wide transcriptome analyses adding spatial resolution to the molecular information. This level of resolution is important for the understanding of many biological processes and potentially relevant for the clinical management of cancer patients.At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.
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Battiste, Henri. "A Comparison of Graphics-Based versus Text-Based Online Probe Methods for Predicting Performance of Air Traffic Controllers." Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10752482.
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The present study compared the validity of a new graphic probe presentation technique for the Situation Awareness Present Method (SPAM) with the established traditional text-based probe presentation method. Three primary research questions were to be answered: 1) Which method of assessing situation awareness will best predict air traffic controller (ATCo) performance? 2) Will the method of probe administration, graphics-based vs. text-based, affect the time to respond to the question?, and 3) Will the method of administration, graphics-based vs. text-based, affect the accuracy of probe responses? Participants performed a simulated air traffic control task using a Multi Aircraft Control System (MACS), which is a simulated mid-fidelity ATCo environment. SPAM probe questions were presented on an adjacent computer. Two manipulations were used during the course of this study: 1) the amount of aircraft in the sector at a given time (traffic density), and 2) the probe presentation technique (Graphic vs. Text-based), with the traditional SPAM dependent variables of probe accuracy, subjective workload, workload latency, and probe question latency. First, the findings of the present study show the shorter response time of text-based probes. Second, the findings of the present study show text-based probes to generate more accurate participant responses. Lastly, the findings of the present study suggest both text-based and graphic probes predict aspects of ATCo performance. However, only specific text-based probe questions predict Losses of Separation, the primary measurement of ATCo safety. While significant findings were discovered during the course of the present experiment, further research is needed to determine the validity and reliability of the present findings.
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Karabicak, Seher. "Application Of Surface-enhanced Raman Scattering (sers) Method For Genetic Analyses." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613130/index.pdf.
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Raman spectroscopy offers much better spectral selectivity but its usage has been limited by its poor sensitivity. The discovery of surface-enhanced Raman scattering (SERS) effect, which results in increased sensitivities of up to 108-fold for some compounds, has eliminated this drawback.
A new SERS active substrate was developed in this study. Silver nanoparticle-doped polyvinyl alcohol (PVA) coated SERS substrate prepared through chemical and electrochemical reduction of silver particles dispersed in the polymer matrix. Performances of the substrates were evaluated with some biologically important compounds.
The specific detection of DNA has gained significance in recent years since increasingly DNA sequences of different organisms are being assigned. Such sequence knowledge can be employed for identification of the genes of microorganisms or diseases. In this study, specific proteasome gene sequences were detected both label free spectrophotometric detection and SERS detection. In label free spectrophotometic detection, proteasome gene probe and complementary target gene sequence were attached to the gold nanoparticles separately. Then, the target and probe oligonucleotide-modified gold solutions were mixed for hybridization and the shift in the surface plasmon absorption band of gold nanoparticles were followed.
SERS detection of specific nucleic acid sequences are mainly based on hybridization of DNA targets to complementary probe sequences, which are labelled with SERS active dyes. In this study, to show correlation between circulating proteasome levels and disease state we suggest a Raman spectroscopic technique that uses SERGen probes. This novel approach deals with specific detection of elevated or decreased levels of proteasome genes&rsquotranscription in patients as an alternative to available enzyme activity measurement methods. First, SERGen probes were prepared using SERS active labels and specific proteasome gene sequences. Then DNA targets to complementary SERGen probe sequences were hybridized and SERS active label peak was followed.
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Welzel, Thomas. "Time-resolved characterisation of pulsed magnetron discharges for the deposition of thin films with plasma diagnostic methods." Doctoral thesis, Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-81968.
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Research on the characterisation and understanding of pulsed magnetron discharges used for the deposition of thin, especially dielectric, films has been carried out between 2003 and 2008 at Chemnitz University of Technology. This thesis is a collection and summary of the original research during this period. In the main part of the thesis, work published in peer-reviewed scientific papers is summarised and yet unpublished results are given in more detail. Different aspects highlighted in the publications are described in a general context of the characterisation of the pulsed discharges for the principal understanding. The cross-linking of the published results is addressed and where necessary extensions to the publications are given. The main part is organised in three sections. In the first one, basics of pulsed magnetron discharges, their application, and important questions are summarised. The second section describes general results and physics of the discharges that have been obtained during the research work. It also emphasises the successful development or modifications of experimental techniques for the time-resolved characterisation. The third section addresses the possibilities to modify and control the process by external parameters that are typically accessible during the application or required by it. An appendix to the thesis comprises selected published research work which is made available as reprints of the original publications. Other publications which are not included as reprints are referenced to in the main partUntersuchungen zur Charakterisierung und zum Verständnis gepulster Magnetronentladungen, die zur Abscheidung von dünnen Schichten, besonders von dielektrischen Schichten, verwendet werden, wurden in den Jahren 2003 bis 2008 an der Technischen Universität Chemnitz durchgeführt. Diese Arbeit ist eine Sammlung und Zusammenfassung von neuen Forschungsergebnissen, die in diesem Zeitraum gewonnen wurden. Im Hauptteil der Habilitationsschrift werden die Arbeiten, die in referierten wissenschaftlichen Zeitschriften erschienen sind, zusammengefasst und noch unveröffentlichte Ergebnisse ausführlicher beschrieben. Verschiedene Aspekte, die in den Veröffentlichungen herausgestrichen wurden, werden in einem allgemeinen Zusammenhang der Charakterisierung gepulster Entladungen für ein prinzipielles Verständnis dargestellt. Querverbindungen zwischen den veröffentlichten Ergebnissen werden herausgearbeitet und wo nötig werden Erweiterungen der Originalveröffentlichungen vorgenommen. Der Hauptteil der Habilitationsschrift ist in drei Abschnitte unterteilt. Im ersten Teil werden Grundzüge gepulster Entladungen, ihre Anwendung und wesentliche Fragestellungen zusammengefasst. Der zweite Abschnitt beschreibt allgemeine Ergebnisse und die Physik der Entladungen, die während der Forschungsarbeit herausgearbeitet wurden. Er stellt auch die erfolgreiche Neuentwicklung oder Modifikation von Messtechniken zur zeitaufgelösten Charakterisierung heraus. Der dritte Abschnitt befasst sich mit den Möglichkeiten, den Beschichtungsprozess durch externe Parameter, die typischerweise während der Prozessanwendung zugänglich oder auch erforderlich sind, zu modifizieren und zu steuern. Der Anhang der Schrift beinhaltet ausgewählte Originalveröffentlichungen, die in Form von Reprints zugänglich gemacht werden. Andere Veröffentlichungen, die nicht im Anhang enthalten sind, werden im Hauptteil zitiert
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Welzel, Thomas. "Time-resolved characterisation of pulsed magnetron discharges for the deposition of thin films with plasma diagnostic methods." Doctoral thesis, Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-201000922.
Full textAbstract:
Research on the characterisation and understanding of pulsed magnetron discharges used for the deposition of thin, especially dielectric, films has been carried out between 2003 and 2008 at Chemnitz University of Technology. This thesis is a collection and summary of the original research during this period. In the main part of the thesis, work published in peer-reviewed scientific papers is summarised and yet unpublished results are given in more detail. Different aspects highlighted in the publications are described in a general context of the characterisation of the pulsed discharges for the principal understanding. The cross-linking of the published results is addressed and where necessary extensions to the publications are given. The main part is organised in three sections. In the first one, basics of pulsed magnetron discharges, their application, and important questions are summarised. The second section describes general results and physics of the discharges that have been obtained during the research work. It also emphasises the successful development or modifications of experimental techniques for the time-resolved characterisation. The third section addresses the possibilities to modify and control the process by external parameters that are typically accessible during the application or required by it. An appendix to the thesis comprises selected published research work which is made available as reprints of the original publications. Other publications which are not included as reprints are referenced to in the main partUntersuchungen zur Charakterisierung und zum Verständnis gepulster Magnetronentladungen, die zur Abscheidung von dünnen Schichten, besonders von dielektrischen Schichten, verwendet werden, wurden in den Jahren 2003 bis 2008 an der Technischen Universität Chemnitz durchgeführt. Diese Arbeit ist eine Sammlung und Zusammenfassung von neuen Forschungsergebnissen, die in diesem Zeitraum gewonnen wurden. Im Hauptteil der Habilitationsschrift werden die Arbeiten, die in referierten wissenschaftlichen Zeitschriften erschienen sind, zusammengefasst und noch unveröffentlichte Ergebnisse ausführlicher beschrieben. Verschiedene Aspekte, die in den Veröffentlichungen herausgestrichen wurden, werden in einem allgemeinen Zusammenhang der Charakterisierung gepulster Entladungen für ein prinzipielles Verständnis dargestellt. Querverbindungen zwischen den veröffentlichten Ergebnissen werden herausgearbeitet und wo nötig werden Erweiterungen der Originalveröffentlichungen vorgenommen. Der Hauptteil der Habilitationsschrift ist in drei Abschnitte unterteilt. Im ersten Teil werden Grundzüge gepulster Entladungen, ihre Anwendung und wesentliche Fragestellungen zusammengefasst. Der zweite Abschnitt beschreibt allgemeine Ergebnisse und die Physik der Entladungen, die während der Forschungsarbeit herausgearbeitet wurden. Er stellt auch die erfolgreiche Neuentwicklung oder Modifikation von Messtechniken zur zeitaufgelösten Charakterisierung heraus. Der dritte Abschnitt befasst sich mit den Möglichkeiten, den Beschichtungsprozess durch externe Parameter, die typischerweise während der Prozessanwendung zugänglich oder auch erforderlich sind, zu modifizieren und zu steuern. Der Anhang der Schrift beinhaltet ausgewählte Originalveröffentlichungen, die in Form von Reprints zugänglich gemacht werden. Andere Veröffentlichungen, die nicht im Anhang enthalten sind, werden im Hauptteil zitiert
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Gouin, Céline. "Numerical methods for the prediction of gravitational lensing signal as a probe of the mass content on the Universe." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS106/document.
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Les relevés à venir comme Euclid, LSST et WFIRST vont nous ouvrir la perspective d’étudier l’univers profond. Pour ces grands relevés, l’astigmatisme cosmique correspond à une sonde indispensable pour étudier la nature de l’énergie noire et la matière noire. Compte tenu de la précision attendue par ces observations, nous devons faire des prédictions basées sur des simulations correspondant à l’état de l’art afin de quantifier avec précision la variance, les biais et les dégénérescences potentielles liés aux baryons. Dans ce contexte, ma thèse se focalise sur la construction d’estimateurs précis basés sur les observables de lentillage. La première partie de ma thèse consiste à caractériser la géométrie des grandes structures par astigmatisme cosmique (Gouin et al. 2017). Une décomposition multipolaire du signal est appliquée afin de quantifier la distribution azimutale de la matière noire, centrée sur les amas. Les propriétés statistiques de ces moments sont estimées à partir d’une simulation cosmologique. Les distorsions harmoniques calculées dans le voisinage des amas tracent la structure filamentaire. Un plus grand nombre de filaments semblent connectés aux amas de forte masse. Dans la dernière partie de ma thèse, je synthétise le signal d’astigmatisme cosmique dans le cône de lumière de la simulation Horizon AGN. Pour ce faire, je propage les rayons de lumière le long du cône dans l’approximation des plans de lentillage multiples. L’effet des baryons est significatif dans la statistique du cisaillement aux échelles angulaires inférieures à l’arc-minute. Le signal de cisaillement galaxie-galaxie est comparée aux observations récentes, et semble être en bon accordUpcoming weak lensing surveys such as Euclid, LSST and WFIRST will provide an unprecedented opportunity to investigate the dark Universe. Through these large scale surveys, gravitational lensing is an indispensable cosmological probe to investigate the dark energy and the dark matter. Due to the new level of accuracy in observations, we must perform cosmological predictions in state-of-art simulations, to precisely quantify its variances, biases and potential degeneracies coming from baryonic physics. In this context, my thesis focuses on the construction of accurate weak lensing observables. The first part of my PhD work characterises the geometry of large-scale structure through weak lensing (Gouin et al. 2017). I relied on multipolar decomposition of weak lensing signal to quantify the azimuthal distribution of dark matter centred on galaxy clusters. The statistical properties of these moments are estimated from a large N-body simulation. The harmonic distortions computed in the vicinity of clusters appear to trace the filamentary structure. Larger number of filaments seem to be connected to high-mass clusters.The detection level of this statistical estimator is estimated. In the last part of my thesis, I mock the weak gravitational lensing signal in the light-cone of the Horizon-AGN simulation (Gouin et al. 2019). To do so, I propagate light-rays along the light-cone in the multiple-lens-plane approximation. The impact of baryons is significant in cosmic shear statistics for angular scales below a few arcmins. In addition, the galaxy-galaxy lensing signal is compared to current observational measurements (Leauthaud et al. 2017), and seems in good agreement
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Barve, Aabha. "Development of an Optical Method for the Detection of Homocysteine as a Disease Biomarker Using Fluorescein-Aldehydes." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2221.
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Homocysteine is a natural occurring aminothiol. It is an intermediate product in the metabolism of methionine. Methionine is an essential amino acid required for protein synthesis. Metabolic irregularities disrupt homocysteine levels in plasma. Elevated homocysteine levels are directly linked to folate and cobalamin (vitamin B12) deficiencies, and are an independent risk factor for cardiovascular diseases. High homocysteine levels have also been associated with Alzheimer's, osteoporosis, renal failure, cancer, birth defects and pregnancy complications. The association of elevated homocysteine levels with cardiovascular disease and other diseases has generated great interest in the detection of homocysteine.
An optical method for the detection of homocysteine has been developed using fluorescein mono- and dialdehydes. Selectivity for homocysteine was achieved based on the characteristic differences between 5- and 6-membered ring heterocyclic amines formed upon the reaction with fluorescein mono- and dialdehydes. 6-membered ring homocysteine-derived thiazinane-4-carboxylic acids were found to be more basic than 5-membered cysteine-derived thiazolidine-4-carboxylic acids. Fluorescence enhancement in response to homocysteine was thus attained by tuning pH and excitation wavelengths. Furthermore, the design and synthesis of a more sensitive fluorophore, fluorescein tri aldehyde has been accomplished based on the aforementioned findings to enable the detection of homocysteine at physiological levels. Calculations of Mulliken charges revealed that the formation of thiazinanes results in modulation of the electron density on the fluorophore leading to higher fluorescence.
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Fox, Brandon S. "In-Pile Thermal Conductivity Measurement Methods for Nuclear Fuels." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/660.
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Measuring nuclear fuel thermal conductivity in-pile can provide much needed data for understanding fuel performance during irradiation and yield thermophysical property data needed for simulation codes and fuel databases. The objective of this research is to develop and compare two in-pile thermal conductivity methods in a laboratory setting using surrogate fuel materials.
A steady-state radial heat flow method was investigated to understand its viability as an in-pile steady-state thermal conductivity technique. By using Joule heating to simulate volumetric heat generation within a surrogate fuel rod, thermal conductivity was measured with two thermocouples at different radial positions within the rod. Examinations were completed on two batches of surrogate materials over the temperature range of 500 to 700 °C. The selected surrogate rod was fabricated from the only material identified to possess the required thermal conductivity and electrical resistivity required for the selected laboratory approach. Evaluations estimated a measurement uncertainty of 12% and values were within 33% of values obtained using laboratory material property measurement systems for this surrogate material. Results indicate that the selected surrogate rod material limited the ability to assess this approach at higher temperatures in a laboratory setting.
A transient needle probe method adapted from American Standard Test Method standards was also used to measure temperature-dependent thermal conductivity of surrogate fuel rod materials for temperatures ranging from room temperature to 400 °C. The needle probe has a heating element and a temperature sensor contained in a metal sheath, and it is inserted into the surrogate fuel rod whose thermal conductivity is to be measured. The thermal conductivity is calculated from the power applied to the heating element, and the temperature rise detected in the sample. Needle probes were designed and fabricated using materials recommended for in-pile application. Scoping room-temperature values obtained using the needle probe method were within acceptable accuracies defined by the ASTM needle probe reference standard. Temperature-dependent values were within 2% of values for the well-characterized ASTM recommended reference material, fused silica. A measurement uncertainty under 6% was calculated for the needle probe method.
As a result of this study, the needle probe method was selected for additional testing at the Idaho National Laboratory for anticipated testing in Materials Test Reactors. This would result in the first-ever transient in-pile thermal conductivity sensor.
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Ragnarsson, Lotten. "Conantokin probes of NMDA receptors in mammalian CNS : implications for Alzheimer's disease /." [St. Lucia, Qld], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18257.pdf.
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Takaoka, Yosuke. "Development of New Methods for Chemical Labeling, Functionalization and Detection of Proteins by Ligand-tethered Probes." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120896.
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TOLOZA, CARLOS ALBERTO TOLOZA. "SPECTROANALYTICAL METHODS USING GRAPHENE QUANTUM DOTS AS PHOTOLUMINESCENT PROBES FOR THE DETERMINATION OF ANALYTES OF BIOLOGICAL AND PHARMACOLOGICAL INTEREST." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35904@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
FUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIRO
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
BOLSA NOTA 10
O presente trabalho teve como objetivo o desenvolvimento de métodos espectroanalíticos capazes de determinar indiretamente analitos de interesse biológico e farmacológico que possuem fraca atividade óptica no UV-vis (no caso, captopril, histamina e sulfato de canamicina). Embora muitos métodos para quantificar esses analitos estejam reportados, muitos dependem da derivatização química do analito, procedimento considerado complexo e trabalhoso para fazer tais analitos absorverem e emitirem no UV-vis. Por isso, a proposta de uso de pontos quânticos fotoluminescentes é interessante, pois permitem, em condições ajustadas, respostas analíticas que proporcionam a determinação indireta dos analitos de interesse em concentrações da ordem de até 10-8 mol L-1. A determinação do captopril foi proposta utilizando pontos quânticos de grafeno aminofuncionalizados com uso de glutationa (GQDs-amino). O captopril induziu a supressão e o deslocamento espectral (para o vermelho) da fotoluminescência da dispersão aquosa dos GQDs-amino. Por outro lado, quando Fe3+ foi usado como um mediador que gera uma supressão da fotoluminescência da dispersão de GQDs-amino, a adição de captopril restabelece a fotoluminescência original dos pontos quânticos. Em condições experimentais ajustadas, a magnitude da supressão ou de deslocamento espectral da fotoluminescência dos GQDs-amino pode ser relacionada com a concentração de captopril. Em ambos os casos, a resposta linearizada abrangeu três ordens de grandeza (10-6 a 10-4 mol L-1). Em contrapartida, a abordagem de restauração do sinal da sonda, previamente suprimida com Fe3+, também se mostrou útil do ponto de vista analítico. As abordagens propostas foram testadas com a determinação de captopril em amostras simuladas e em formulações farmacêuticas comerciais. O deslocamento 10 espectral a partir da sonda GQDs-amino e ativação/desativação da fotoluminescência utilizando GQDs-amino-Fe3+ resultou em recuperações satisfatórias, mostrando o potencial de detecção quantitativo do método. No estudo com a histamina, avaliou-se o comportamento fotoluminescente da dispersão aquosa de GQDs-amino na presença de histamina com interação mediada por diferentes íons metálicos. Os resultados revelaram que uma interação mais forte e seletiva existia na presença de Eu3+, Fe3+ e Cu2+. A sensibilidade das curvas de supressão de fotoluminescência normalizada (Ks) indicou uma interação dez vezes mais forte da histamina com a superfície dos GQDs na presença de Fe3+. A resposta linear observada nos GQDs-amino-Fe3+ (luminescência medida a 345/435 nm) abrangeu a concentração de histamina de 4,3 × 10-7 mol L-1 (limite de quantificação) até 3,2 × 10-5 mol L-1. A dispersão de GQDs-amino-Fe3+ foi usada como sonda na análise de amostras de atum após extração do analito em cartucho fase sólida catiônica. Os resultados analíticos foram estatisticamente semelhantes aos obtidos com um método baseado na cromatografia líquida com detecção fluorimétrica (após derivatização química da histamina). A determinação do sulfato de canamicina foi feita medindoo efeito que ela exerce sobre a fotoluminescência dos GQDs-amino associados às nanopartículas de ouro (AuNPs), que foram produzidas pela redução de AuCl4 com NaBH4 em uma dispersão aquosa de GQDs-amino (obtido pela pirólise de ácido cítrico e glutationa) contendo também o agente tensoativo catiônico CTAB. O sistema AuNPs-GQDs-amino-CTAB apresentou fotoluminescência suprimida, que foi amplificada na presença de canamicina. Sob condições experimentais ajustadas, a ampliação da fotoluminescência do nanomaterial em função da concentração de analito se mostrou linear e abrangeu três ordens de grandeza (10-7 a 10-5 mol L-1). O uso de extração em fase sólida com um cartucho empacotado com um polímero molecularmente impresso (seletivo para aminoglicosídeos) assegurou a seletividade nas determinações de sulfato de canamicina feitas em vacina da febre amarela e em formula�
The objective of the present work was the development of spectroanalytical methods capable of indirectly determining analytes of biological and pharmacological interest that present inherent weak optical activity in UV-vis (in this case, captopril, histamine and kanamycin sulfate). Although many methods to quantify these analytes are reported, many of these depend on chemical derivatization, a procedure considered complex and laborious to promote UV-vis absorption and luminescence. Therefore, the proposed use of photoluminescent quantum dots is interesting since they allow, under adjusted conditions, analytical responses that allow the indirect determination of the analytes of interest in concentrations of the order of down to 10-8 mol L-1. The determination of captopril was proposed using graphene quantum dots aminofunctionalized using glutathione as a precursor (GQDs-amino). Captopril induced photoluminescence suppression and spectral red-shift from the aqueous dispersion of GQDs-amino. In contrast, when Fe3+ is used as a mediator, it generates a suppression of the photoluminescence of the GQD-amino dispersion and the addition of captopril restored the original photoluminescence of the quantum dots. In adjusted experimental conditions, photoluminescence suppression of the GQDs-amino, as a function of the captopril concentration, can be related both to the magnitude of the suppression and to the spectral shift. In both cases, the linearized response covered three orders of magnitude (10-6 to 10-4 mol L-1). In contrast, the probe signal restoration of the previously Fe3+ suppressed photoluminescent GQDs, also proved to be analytically useful. The proposed approaches were tested by the determination of captopril in simulated samples and in commercial pharmaceutical formulations. Spectral shift from the GQDs-amino probe and the photoluminescence on/off approach (using GQDs-amino-Fe3+ probe) resulted in satisfactory recoveries, showing the quantitative capability of the method. In the work concerning histamine, the photoluminescent behavior of the aqueous dispersion of GQDs-amino in the presence of this amino acid was studied in function of different interaction mediators (metal ions). The results revealed that strong and selective interaction existed in the presence of Eu3+, Fe3+ and Cu2+. The sensitivity of normalized photoluminescence (Ks) suppression curves indicated a ten-fold stronger interaction of histamine with the surface of GQDs in the presence of Fe3+. The linear response observed in the GQDs-amino-Fe3+ (luminescence measured at 345/435 nm) covered the histamine concentration of 4.3 × 10-7 mol L-1 (quantification limit) to 3.2 × 10-5 mol L-1. The GQDs-amino-Fe3+ was applied as a probe in the analysis of tuna fish samples after solid phase extraction (SPE) of the analyte using a cationic solid phase. The analytical results were statistically similar to those obtained with a method based on liquid chromatography with fluorimetric detection (after chemical derivatization of histamine). The determination of kanamycin sulfate was made by measuring the effect it exerts on the photoluminescence of gold nanoparticles (AuNPs) associated GQDs, that were produced by the reduction of AuCl4 with NaBH4 in an aqueous dispersion of GQDs-amino (obtained by pyrolysis of citric acid and glutathione) also containing the cationic surfactant CTAB. The AuNPs-GQDs-amino-CTAB system showed a suppressed photoluminescence, which was amplified in the presence of kanamycin. Under adjusted experimental conditions, the magnification of the photoluminescence of the nanomaterial as a function of the analyte concentration was linear and covered three orders of magnitude (10-7 to 10-5 mol L-1). The use of solid phase extraction with a cartridge packed with a molecularly imprinted polymer (selective for aminoglycosides) ensured selectivity in the determinations made in yellow fever vaccine and in veterinary pharmaceutical formulations. The analytical results were statistically similar to those obtained with an HPLC based method with fluorimetri
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Rodriguez, Frausto Heriberto. "Development and analytical validation of a gas chromatography-mass spectrometry method for the assessment of gastrointestinal permeability and intestinal absorptive capacity in dogs." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3257.
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Wischert, Raphael. "Theoretical and experimental study of defect sites on partially hydrated γ-alumina : stability, reactivity towards small molecules and implications for single-site catalysts." Lyon, Ecole normale supérieure, 2010. http://www.theses.fr/2010ENSL0590.
Full textAbstract:
Quand des alumines de transition (gamme et delta) sont prétraitées à hautes températures (au dessus de 400°C) des « défauts » de surface avec une très forte acidité de Lewis sont formés. Leur densité atteint un maximum pour une température de prétraitement de 700°C, puis elle décroit à plus haute température. En combinant des calculs DFT (réactivité et spectroscopie) et des expériences (IR, RMN, DRX et études de réactivité) la structure, la stabilité et la réactivité de ces site envers des petites molécules sondes (N2, H2 et CH4) ont été étudiés en tenant compte de l’hydratation de la surface (densité d’OH, qui décroit en fonction de la température de prétraitement). Cette approche a démontré que i) N2 s’adsorbe sélectivement sur des sites AlIII (coordination), alors que H2 et CH4 sont dissociés sur des sites Al-O, en particulier sur les sites AlIII, avec formation d'espèces Al-H et Al-CH3 et de groupements OH (dissociation hétérolytique), ii) l’hydratation a deux rôles : stabiliser la surface (110) qui contient ces sites AlIII et augmenter la basicité de certains atomes d’oxygène de surface et en conséquence leur réactivité envers H2 et CH4. Cela explique la température optimale de prétraitement de 700°C (la densité de AlIII est augmentée sans changement structural de l’alumine ; au dessus de cette température l’alumine adopte une phase cristalline plus stable, théta et enfin alpha, qui ne présentent pas ces sites AlIII). Finalement, dans le contexte de systèmes catalytiques supportées sur alumine, ces défauts sont proposés comme élément clef pour la génération du site actif de CH3ReO3/alumine-gamma, un catalyseur de métathèse hautement efficaceWhen pre-treated at high temperatures (above 400 °C), very strong Lewis acid sites (“defect sites”) are formed on transition alumina (gamma and delta) with an optimal site density found for pre-treatment temperatures of ca. 700 °C, before their density decreases with higher thermal treatment. Combining periodic DFT calculations (reaction pathways and spectroscopy) and experiments (IR, NMR, XRD and reactivity studies) the structure, the stability and the reactivity of these sites towards small probe molecules (N2, H2 and CH4) was investigated taking into account hydration of the surface (OH density, which decreases function of thermal pre-treatment). This approach showed that i) N2 adsorbs selectively on AlIII sites (coordination), while H2 and CH4 are dissociated on Al-O sites, in particular on AlIII, to form Al-H and Al-CH3 species, respectively, along with OH-groups (heterolytic splitting). Ii) Hydration has a dual role: stabilizing the (110) surfaces exhibiting these AlIII sites and increasing the basicity of some O atoms and thereby their reactivity towards H2 and CH4, hence the optimal pre-treatment temperature (increasing the AlIII site density without changing the structure of alumina; above 700 °C alumina evolves towards theta and alpha phases, which do not present these sites). Finally, in the context of supported alumina systems, these defect sites are proposed to be the key to generate the active sites of CH3ReO3/gamma-Al2O3, a highly efficient alkene metathesis catalyst