Dissertations / Theses: 'Dye coupling'

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Klysubun, Prapong. "Nonlinear optical studies of dye-doped nematic liquid crystals." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/26577.

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Nematic liquid crystals possess large optical nonlinearities owing to their large refractive index anisotropy coupled with the collective molecular reorientation. Doping absorbing dyes into liquid crystals increases their optical responses significantly due to increased absorption in the visible region, absorption-induced intermolecular torque, cis-trans photoisomerization, and other guest-host effects. The guest-host mixtures can be employed in display applications, optical storage devices, and others. In this dissertation, nonlinear optical studies were carried out on dye-doped nematic liquid crystal cells. The main objectives of the studies were to distinguish and characterize the several processes that can lead to the formation of dynamic gratings of different types in the samples, and to study the photorefractive and the orientational responses of these samples. Furthermore, we tried to explain and model the dynamical behaviors of the observed grating formations. The experimental techniques employed in this study include asymmetric two-beam coupling, forced light scattering, and polarization holographic method. The asymmetric two-beam coupling experiments revealed that the induced grating was a photorefractive phase grating created by the nematic director reorientation within the plane of incidence. The dynamics of the beam coupling showed that two different mechanisms with different temporal responses were involved. The grating translation technique identified both gratings as pure photorefractive index gratings with phase shifts of ~ p/2 between the grating and the interference pattern. In addition, the dynamical behavior of the grating formation, obtained from forced light scattering experiments, also exhibited a two-time constant response. The dynamical behaviors of the build-up and decay of the photocurrent were investigated. The two dynamics exhibited both a two-time constant behavior, suggesting that the origin of the two-time constant dynamics observed in the two-beam coupling and the forced light scattering experiments resides in the process of photo-charge generation. The photorefractive gain coefficients were found to be in the range of 100 â 400 cm-1. The values of the nonlinear optical Kerr index (~ 0.08 cm2/W) measured in samples with certain dye/liquid crystal combinations are higher than what has been observed in other dye-doped nematics and other liquid crystal/polymer systems. All the samples showed a threshold behavior with respect to the magnitude of the applied electric field. This threshold behavior was observed both in forced light scattering experiments and polarization holographic experiments. We believe that the origin of this threshold lies in the process of photogeneration, which was found to exhibit the same threshold behavior at the same value of the applied voltage. An asymmetry of the photorefractive gain with respect to the direction of the applied electric field was observed in samples with high dye concentration. This was attributed to the beam fanning effect, which has also been observed in other high-gain photorefractive materials. Polarization holographic measurements showed that the dye enhancement effect is primarily due to the intermolecular interaction between the dye molecules and the liquid crystal host, and that the trans-cis photoisomerization plays a lesser role. The photoinduced orientational response was also studied using polarization holographic experiments. A number of observations confirmed that the birefringent grating is due to the nematic director reorientation within the plane of incidence, under the combined effect of the applied electric field and the optical field. The diffraction efficiency was found to depend linearly on the writing beam power, while the dependence of the self-diffraction efficiency on the writing beam power roughly assumes a cubic relationship. The dynamical behavior of the birefringent grating formation was investigated. The build-up dynamics was found to be best modeled as a double-time constant response, while the decay is best fitted by a single exponential. The response of the samples to an oscillating electric field was studied as a function of the modulation frequency. Very interesting and reproducible dynamics was observed, revealing the complex dynamical response of the liquid crystal director to the magnitude and rate of change of an applied electric field. The small signal response was also measured, but did not reveal any sign of a resonance behavior. The conductivity and the photoconductivity of the samples were measured. The relationship between the measured current and the applied voltage was found to be cubic at low applied voltage, and to become linear at higher applied voltage. We could explain this behavior using a double-charge-injection-in-a-weak-electrolyte model, but this is only one of the possible mechanisms that could explain this behavior. The photocurrent was found to increase linearly with the illumination power, which indicates that the charge carrier recombination rate is proportional to the carrier density. The measured electrical conductivity was found to be proportional to the square root of the dye concentration, confirming the validity of the proposed charge-injection model. Ph. D.

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Isakson, Brant, Colin Olsen, and Scott Boitano. "Laminin-332 alters connexin profile, dye coupling and intercellular Ca2+ waves in ciliated tracheal epithelial cells." BioMed Central, 2006. http://hdl.handle.net/10150/610241.

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BACKGROUND:Tracheal epithelial cells are anchored to a dynamic basement membrane that contains a variety of extracellular matrix proteins including collagens and laminins. During development, wound repair and disease of the airway epithelium, significant changes in extracellular matrix proteins may directly affect cell migration, differentiation and events mediated by intercellular communication. We hypothesized that alterations in cell matrix, specifically type I collagen and laminin alpha3beta3gamma2 (LM-332) proteins within the matrix, directly affect intercellular communication in ciliated rabbit tracheal epithelial cells (RTEC).METHODS:Functional coupling of RTEC was monitored by microinjection of the negatively charged fluorescent dyes, Lucifer Yellow and Alexa 350, into ciliated RTEC grown on either a LM-332/collagen or collagen matrix. Coupling of physiologically significant molecules was evaluated by the mechanism and extent of propagated intercellular Ca2+ waves. Expression of connexin (Cx) mRNA and proteins were assayed by reverse transcriptase - polymerase chain reaction and immunocytochemistry, respectively.RESULTS:When compared to RTEC grown on collagen alone, RTEC grown on LM-332/collagen displayed a significant increase in dye transfer. Although mechanical stimulation of RTEC grown on either LM-332/collagen or collagen alone resulted in intercellular Ca2+ waves, the mechanism of transfer was dependent on matrix: RTEC grown on LM-332/collagen propagated Ca2+waves via extracellular purinergic signaling whereas RTEC grown on collagen used gap junctions. Comparison of RTEC grown on collagen or LM-332/collagen matrices revealed a reorganization of Cx26, Cx43 and Cx46 proteins.CONCLUSION:Alterations in airway basement membrane proteins such as LM-332 can induce connexin reorganizations and result in altered cellular communication mechanisms that could contribute to airway tissue function.

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Nilsing, Mattias. "Computational Investigation of Dye-Sensitized Solar Cells." Doctoral thesis, Uppsala universitet, Avdelningen för kvantkemi, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7673.

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Interfaces between semiconductors and adsorbed molecules form a central area of research in surface science, occurring in many different contexts. One such application is the so-called Dye-Sensitized Solar Cell (DSSC) where the nanostructured dye-semiconductor interface is of special interest, as this is where the most important ultrafast electron transfer process takes place. In this thesis, structural and electronic aspects of these interfaces have been studied theoretically using quantum chemical computations applied to realistic dye-semiconductor systems. Periodic boundary conditions and large cluster models have been employed together with hybrid HF-DFT functionals in the modeling of nanostructured titanium dioxide. A study of the adsorption of a pyridine molecule via phosphonic and carboxylic acid anchor groups to an anatase (101) surface showed that the choice of anchor group affects the strength of the bindings as well as the electronic interaction at the dye-TiO2 interface. The calculated interfacial electronic coupling was found to be stronger for carboxylic acid than for phosphonic acid, while phosphonic acid binds significantly stronger than carboxylic acid to the TiO2 surface. Atomistic and electronic structure of realistic dye-semiconductor interfaces were reported for RuII-bis-terpyridine dyes on a large anatase TiO2 cluster and perylene dyes on a periodic rutile (110) TiO2 surface. The results show strong influence of anchor and inserted spacer groups on adsorption and electronic properties. Also in these cases, the phosphonic acid anchor group was found to bind the dyes significantly stronger to the surface than the carboxylic acid anchor, while the interfacial electronic coupling was stronger for the carboxylic anchor. The estimated electron injection times were twice as fast for the carboxylic anchor compared to the phosphonic anchor. Moreover, the electronic coupling was affected by the choice of spacer group, where unsaturated spacer groups were found to mediate electron transfer more efficiently than saturated ones.

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Türschmann, Pierre [Verfasser], Vahid [Akademischer Betreuer] Sandoghdar, Edward [Gutachter] Hinds, and Ulrike [Gutachter] Woggon. "Coherent Coupling of Single Organic Dye Molecules to Optical Nanoguides / Pierre Türschmann ; Gutachter: Edward Hinds, Ulrike Woggon ; Betreuer: Vahid Sandoghdar." Erlangen : FAU University Press, 2018. http://d-nb.info/1162340320/34.

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Lundqvist, Maria J. "Quantum Chemical Modeling of Dye-Sensitized Titanium Dioxide : Ruthenium Polypyridyl and Perylene Dyes, TiO2 Nanoparticles, and Their Interfaces." Doctoral thesis, Uppsala universitet, Kvantkemi, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7141.

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Quantum chemical calculations have been used to model dye-sensitized nanostructured titanium dioxide systems that can be used in solar cells for solar energy to electricity conversion. Structural, electronic and spectral properties of isolated dyes and both bare and dye-sensitized TiO2 have been calculated with density functional theory, providing detailed information about both the separate parts and the dye-TiO2 interface. The connection between the geometry, the ligand field splitting and the lifetime of the triplet metal-to-ligand charge transfer (MLCT) excited state has been explored for a series of ruthenium polypyridyl dyes. Moreover, the relative energetics of MLCT and metal centered triplet excited states have been studied for a number of such systems. It was found that small alterations of the polypyridyl ligands can result in significant changes in ligand field splitting and in the energetics of the triplet states. Attachment of the dyes to the TiO2 surface is achieved via anchor and spacer groups. The influence of such groups on various properties of the dye and their ability to act as mediators of photo-induced surface electron transfer has been studied. Delocalization of the lowest unoccupied dye orbital onto the spacer and/or anchor group indicates that certain unsaturated groups can mediate electron transfer. With a combination of methods that enables efficient computations and a scheme for construction of metal oxide clusters, chemical models for bare TiO2 nanocrystals in the 1-2 nm size range have been developed. The electronic structures show well-developed band structures with essentially no electronic band gap defect states. Atomistic models of the interface between TiO2 nanocrystals and Ru(II)-bis-terpyridine dyes, the so-called N3 dye as well as perylene dyes are reported. Electronic coupling strengths, which provide estimates for the electron injection times, are extracted from the interfacial electronic structure and the lowest electronic excitations are calculated.

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Forker, Roman. "Electronic Coupling Effects and Charge Transfer between Organic Molecules and Metal Surfaces." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-26163.

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We employ a variant of optical absorption spectroscopy, namely in situ differential reflectance spectroscopy (DRS), for an analysis of the structure-properties relations of thin epitaxial organic films. Clear correlations between the spectra and the differently intense coupling to the respective substrates are found. While rather broad and almost structureless spectra are obtained for a quaterrylene (QT) monolayer on Au(111), the spectral shape resembles that of isolated molecules when QT is grown on graphite. We even achieve an efficient electronic decoupling from the subjacent Au(111) by inserting an atomically thin organic spacer layer consisting of hexa-peri-hexabenzocoronene (HBC) with a noticeably dissimilar electronic behavior. These observations are further consolidated by a systematic variation of the metal substrate (Au, Ag, and Al), ranging from inert to rather reactive. For this purpose, 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) is chosen to ensure comparability of the molecular film structures on the different metals, and also because its electronic alignment on various metal surfaces has previously been studied with great intensity. We present evidence for ionized PTCDA at several interfaces and propose the charge transfer to be related to the electronic level alignment governed by interface dipole formation on the respective metals Zur Analyse der Struktur-Eigenschafts-Beziehungen dünner, epitaktischer Molekülfilme wird in situ differentielle Reflexionsspektroskopie (DRS) als Variante der optischen Absorptionsspektroskopie verwendet. Klare Zusammenhänge zwischen den Spektren und der unterschiedlich starken Kopplung zum jeweiligen Substrat werden gefunden. Während man breite und beinahe unstrukturierte Spektren für eine Quaterrylen (QT) Monolage auf Au(111) erhält, ist die spektrale Form von auf Graphit abgeschiedenem QT ähnlich der isolierter Moleküle. Durch Einfügen einer atomar dünnen organischen Zwischenschicht bestehend aus Hexa-peri-hexabenzocoronen (HBC) mit einem deutlich unterschiedlichen elektronischen Verhalten gelingt sogar eine effiziente elektronische Entkopplung vom darunter liegenden Au(111). Diese Ergebnisse werden durch systematische Variation der Metallsubstrate (Au, Ag und Al), welche von inert bis sehr reaktiv reichen, untermauert. Zu diesem Zweck wird 3,4,9,10-Perylentetracarbonsäuredianhydrid (PTCDA) gewählt, um Vergleichbarkeit der molekularen Filmstrukturen zu gewährleisten, und weil dessen elektronische Anordnung auf verschiedenen Metalloberflächen bereits eingehend untersucht worden ist. Wir weisen ionisiertes PTCDA an einigen dieser Grenzflächen nach und schlagen vor, dass der Ladungsübergang mit der elektronischen Niveauanpassung zusammenhängt, welche mit der Ausbildung von Grenzflächendipolen auf den entsprechenden Metallen einhergeht

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Balemarthy, Kasyapa. "Electronic Equalization of High-Speed Multi-mode Fiber Links." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16191.

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The objective of this research is to investigate low-complexity, efficient electronic equalizers to increase the data rate and possibly extend the reach of multi-mode fiber (MMF) links. Specifically, we begin by baselining the performance limits of conventional receivers. A robust, in-house mode solver was developed as part of this research and is currently being used by one of the largest fiber manufacturers in their internal R &D work. A detailed performance assessment of the impact of decision feedback equalizers has been conducted using an extensive model of the installed fiber base. The finite-length DFE results were instrumental in influencing the IEEE 802.3aq standardization effort. In particular, we were able to achieve a reach of 220m but the original goal of 300m was unattainable on 99% of the installed fiber base using DFEs of moderate complexity. A low-cost equalizer that has excellent performance, the bi-directional DFE, was applied to the MMF channel for the first time. The performance of the infinite-length BiDFE was characterized without any constraints on the signal-to-noise ratio and on the receiver front-end, as has been previously done in the literature. A new joint optimization technique that helps the finite-length BiDFE perform significantly better than the infinite-length DFE was developed. It was shown that given a finite number of filter coefficients, the BiDFE utilizes them better than the conventional DFE. Furthermore, a reach of 350-400m at a data rate of 10 Gbps was shown to be feasible with equalizers of complexity similar to that currently available. A multiple-input, multiple-output (MIMO) characterization of the MMF channel was developed through the simultaneous use of both center and offset launch together with the two-segment photo-detector. The potential benefit of MIMO processing for MMF links was demonstrated by computing Shannon capacity bounds. It was established that the 2x2 MIMO channel performs about 1.4 dBo better than the conventional 1x1 link at 10 Gbps with practical joint launch. The MIMO scheme still has a performance improvement of 1dBo at 20 Gbps thereby indicating that 20 Gbps transmission is feasible. Performance evaluation of multi-km MMF links was conducted using a comprehensive model that accounts for mode coupling effects. It was determined that ignoring mode coupling can result in under-estimation of the optimum DFE penalty by as much as 1~dBo for 1km links.

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Marais, Simon. "Phenomena due to strain coupling in phase transitions." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239588.

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Kringle, Loni. "Local Structure and Dynamics of Exciton-Coupled Cyanine Dimers Labeled in DNA." Thesis, University of Oregon, 2018. http://hdl.handle.net/1794/23749.

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Understanding the properties of electronically interacting molecular chromophores, which involve internally coupled electronic-vibrational motions, is important to the spectroscopy of many biological systems. Here we apply linear absorption, circular dichroism, and two-dimensional fluorescence spectroscopy to study the local structure and excited state dynamics of excitonically coupled cyanine dimers that are rigidly positioned within the sugar-phosphate backbones of the DNA. Dimer probes were positioned within the double-stranded DNA duplex and at the single-strand/double-stranded DNA junction to examine the positional dependence of the structural variation and fluctuations. We interpret spectroscopic measurements in terms of the Holstein vibronic dimer model, from which we obtain information about the local conformation of the dimer probe locally within their respective DNA environments. We show that the exciton-coupling strength of the dimer-DNA construct can be systematically varied with temperature below the double-stranded – single-strand DNA denaturation transition. Using time-resolve 2DFS measurements we observed long lived vibronic coherences in the system. The properties of the cyanine DNA construct we determine suggest that it may be employed as a useful model system to test fundamental concepts of protein DNA interactions and the role of electronic-vibrational coherence in electronic energy migration within exciton-coupled biomolecular arrays. This dissertation contains previously published and unpublished co-authored material.

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Lee, Chun-ming Angus, and 李俊明. "Reduction of electromagnetic interference due to electric field coupling on printed circuit board." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B29957709.

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Lee, Chun-ming Angus. "Reduction of electromagnetic interference due to electric field coupling on printed circuit board /." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23501674.

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RAHMAN, S. M. SAYDUR. "Spontaneous Spin Polarization due to Lateral Spin Orbit Coupling in InAs Quantum Point Contacts." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1196103387.

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Rudengren, Isabella, and Julia Dahlberg. "Experimental characterization of focal ratio degradation of optical fibers due to various coupling technologies." Thesis, Uppsala universitet, Institutionen för materialvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447132.

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The goal of this project was to develop a measuring method and software code to determine and compare the focal ratio degradation of optical fibers for two different coupling technologies. One of the couplings used a fusing technology to splice the fiber, and the other coupling used a refractive index matching technology. Also, an optical fiber without any cleaving or splicing was used as a reference. A collimated beam test was developed as a method for measuring the focal ratio degradation for these different fiber couplings, and a software code was developed to process the results of the experiment. Using the collimated beam test and software code, the focal ratio degradation was calculated and compared between the couplings, and the results clearly stated that the reference fiber had the least focal ratio degradation. The fusing technology used for splicing the fiber had in comparison the least focal ratio degradation of the two different coupling technologies. The results were as expected and therefore the developed measuring method and software were estimated to have been carried out successfully. However, improvements to the measuring method and parts of the software could be done, especially regarding the background light which was a substantial source of error. In conclusion, the goal of the project was reached. Inom astronomisk forskning används ofta optiska fibrer som informationslänk mellan teleskop och mätinstrument, eftersom de bidrar till att mätningar blir mer tillförlitliga då vibrationer och yttre miljöfaktorer får en mindre påverkan på resultaten. Inom detta projekt undersöktes ett par olika kopplingar av optiska fibrer och deras ljusförluster inom benämningen FRD (Focal ratio degradation). En mätmetod utvecklades tillsammans med en mjukvara som användes för nödvändiga beräkningar och analyser som ledde till att FRD kunde bestämmas. Metoden som användes kallas collimated beam test och innebar att parallellt ljus skickades in i ena fiberänden, vilket genererade en ring av ljus från den andra fiberänden. Mätningarna utfördes på tre olika fiber: en fiber var klyvd och sedan sammansmält, en annan fiber var klyvd och sedan ihopkopplad med hjälp av en vätska av matchande refraktionsindex och den tredje fibern var inte klyvd och fungerade som referens. Resultaten givna av mätningarna och mjukvaran var som man hade förväntat sig; FRD var minst för referensfibern och som högst för fibern med en koppling där refraktionsindex-matchande vätska användes. Även om det finns goda möjligheter att utveckla och förbättra mätmetoden, påvisades ett godtagbart resultat och målet med projektet ansågs därför vara uppnått.

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Sobering, Ian David. "Mitigating oscillator pulling due to magnetic coupling in monolithic mixed-signal radio-frequency integrated circuits." Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/19755.

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Master of Science Department of Electrical and Computer Engineering W. B. Kuhn An analysis of frequency pulling in a varactor-tuned LC VCO under coupling from an on-chip PA is presented. The large-signal behavior of the VCO's inversion-mode MOS varactors is outlined, and the susceptibility of the VCO to frequency pulling from PA aggressor signals with various modulation schemes is discussed. We show that if the aggressor signal is aperiodic, band-limited, or amplitude-modulated, the varactor-tuned LC VCO will experience frequency pulling due to time-modulation of the varactor capacitance. However, if the aggressor signal has constant-envelope phase modulation, VCO pulling can be eliminated, even in the presence of coupling, through careful choice of VCO frequency and divider ratio. Additional mitigation strategies, including new inductor topologies and system-level architectural choices, are also examined. The analysis is then applied to improve a fully-integrated half-duplex UHF micro- transceiver in which signal coupling between the LO and PA caused frequency pulling that prevented the use of QPSK signaling at certain data rates. We determine that a VCO operating at 4x transmit frequency will be naturally insensitive to pulling from QPSK signals. To validate the proposed solution, a prototype IC containing a pair of QPSK transmitters with integrated 100mW Class-C PAs was designed and fabricated in 0.18um SOI. The transmitters--one utilizing a 2x VCO, one utilizing a 4x VCO-- were designed to closely match the performance of the original microtransceiver when transmitting QPSK data. The transmitter with the 2x VCO experienced frequency pulling from the PA while transmitting QPSK data, but the transmitter with the 4x VCO did not, thereby confirming the analysis in this work. A revision of the microtransceiver was designed in 0.5 [mu]m SOS utilizing an off- chip PA inductor to reduce signal coupling with the VCO. A second revision of the microtransceiver with two prototype transmitters was designed in 0.25 [mu]m SOS uti- lizing 4x VCOs and figure-8 VCO inductors for maximum insensitivity to pulling from QPSK and band-limited modulation, as well as other design improvements that leverage the higher f[subscript]t of the smaller process. Both revisions also include a hardware FSK modulator, a new charge pump, and a redesigned fractional-N synthesizer to attenuate a divided-reference spur in the IF output. These revisions of the radio will enable future researchers to focus on system-level applications where highly-integrated medium-power transceivers with fully-functioning IQ modulation are needed.

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Bauer, Christina Anne. "Synthesis and Structure-Assembly Relationships of Metal Nanoparticles and their Coupling with Two-Photon Organic Dyes." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1265%5F1%5Fm.pdf&type=application/pdf.

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Faucher, Margaux. "Coupling between Monte Carlo neutron transport and thermal-hydraulics for the simulation of transients due to reactivity insertions." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS387/document.

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Dans le contexte de la physique des réacteurs, l’analyse du comportement non stationnaire de la population neutronique avec contre-réactions dans le combustible et dans le modérateur se rend indispensable afin de caractériser les transitoires opérationnels et accidentels dans les systèmes nucléaires et d’en améliorer par conséquent la sûreté. Pour ces configurations non stationnaires, le développement de méthodes Monte-Carlo qui prennent en compte la dépendance en temps du système neutronique, mais aussi le couplage avec les autres physiques, comme la thermohydraulique et la thermomécanique, a pour but de servir de référence aux calculs déterministes.Ce travail de thèse a consisté à mettre en place une chaîne de calcul pour la simulation couplée neutronique Monte-Carlo, avec le code TRIPOLI-4, en conditions non stationnaires et avec prise en compte des contre-réactions thermohydrauliques.Nous avons d'abord considéré les méthodes cinétiques dans TRIPOLI-4, c'est-à-dire avec prise en compte du temps mais sans prise en compte des contre-réactions, en incluant une évaluation des méthodes existantes ainsi que le développement de nouvelles méthodes. Ensuite, nous avons développé un schéma de couplage entre TRIPOLI-4 et le code de thermohydraulique sous-canal SUBCHANFLOW. Enfin, nous avons réalisé une analyse préliminaire de la propagation des incertitudes au sein du calcul couplé sur un modèle simplifié. En effet, les fluctuations statistiques sont inhérentes à notre schéma de par la nature stochastique de TRIPOLI-4. De plus, les équations de la thermohydraulique étant non-linéaires, la propagation des incertitudes au long du calcul doit être étudiée afin de caractériser la convergence du résultat One of the main issues for the study of a reactor behaviour is to model the propagation of the neutrons, described by the Boltzmann transport equation, in the presence of multi-physics phenomena, such as the coupling between neutron transport, thermal-hydraulics and thermomecanics. Thanks to the growing computer power, it is now feasible to apply Monte Carlo methods to the solution of non-stationary transport problems in reactor physics, which play an instrumental role in producing reference numerical solutions for the analysis of transients occurring during normal and accidental behaviour.The goal of this Ph. D. thesis is to develop, verify and test a coupling scheme between the Monte Carlo code TRIPOLI-4 and thermal-hydraulics, so as to provide a reference tool for the simulation of reactivity-induced transients in PWRs.We have first tested the kinetic capabilities of TRIPOLI-4 (i.e., time dependent without thermal-hydraulics feedback), evaluating the different existing methods and implementing new techniques. Then, we have developed a multi-physics interface for TRIPOLI-4, and more specifically a coupling scheme between TRIPOLI-4 and the thermal-hydraulics sub-channel code SUBCHANFLOW. Finally, we have performed a preliminary analysis of the stability of the coupling scheme. Indeed, due to the stochastic nature of the outputs produced by TRIPOLI-4, uncertainties are inherent to our coupling scheme and propagate along the coupling iterations. Moreover, thermal-hydraulics equations are non linear, so the prediction of the propagation of the uncertainties is not straightforward

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Bialas, David [Verfasser], Frank [Gutachter] Würthner, and Roland [Gutachter] Mitrić. "Exciton Coupling in Homo- and Heterostacks of Merocyanine and Perylene Bisimide Dyes / David Bialas ; Gutachter: Frank Würthner, Roland Mitrić." Würzburg : Universität Würzburg, 2017. http://d-nb.info/1137836105/34.

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Randler, Stephan. "Die Mentalität der "Generation X" dargestellt an ausgewählten Romanen und Verfilmungen der englischsprachigen Gegenwartsliteratur /." [S.l. : s.n.], 2004. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11675734.

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Liess, Andreas [Verfasser], Frank [Gutachter] Würthner, and Jens [Gutachter] Pflaum. "Structure-Property Relationships of Merocyanine Dyes in the Solid State: Charge Transport and Exciton Coupling / Andreas Liess ; Gutachter: Frank Würthner, Jens Pflaum." Würzburg : Universität Würzburg, 2017. http://d-nb.info/1138923346/34.

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Glane, Sebastian [Verfasser], Wolfgang H. [Akademischer Betreuer] Müller, Wolfgang H. [Gutachter] Müller, and Kolumban [Gutachter] Hutter. "Variations in the length of day of the earth due to topographic core-mantle coupling in a stratified layer / Sebastian Glane ; Gutachter: Wolfgang H. Müller, Kolumban Hutter ; Betreuer: Wolfgang H. Müller." Berlin : Technische Universität Berlin, 2021. http://d-nb.info/1224965914/34.

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Widarda, Dina Rubiana. "Longitudinal forces in continuously welded rails due to nonlinear track-bridge interaction for loading sequences." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1238081328011-05497.

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The use of continuously welded rails (CWR) governs the longitudinal stress caused by seasonal temperature changes, bending of supporting structure and braking/accelerating due to passing trains. Those three loads have been regulated in Eurocode1 and accomplished by the national codes like DIN Fb-101 in Germany. An additional loading case identified and treated in this thesis is the load due to a change of the coupling stiffness in longitudinal direction between the track and bridge. This additional load occurs as a consequence of the employment of a nonlinear stiffness law which increases the restoring force by a factor of 3 when the situation of the track changes from ‘unloaded’ to ‘loaded’ due to a passing train. This particular phenomenon has not been mentioned in the codes so far though it is a natural consequence of fundamental conditions in those codes. For CWR the longitudinal coupling between the rail and bridge plays an important role. This coupling interface is created either by a ballast, for a ballasted track, or by a fastening system in the case of slab track. The deformation state of the coupling interface characterizes the behaviour of the system, whether elastic or plastic. Therefore, the nonlinear behaviour is valid for the system. To accommodate the nonlinear nature, a sequential loading analysis is used, taking into account the loading history. As the change situation due to a passing train happens in a short time, the influence of the mass acceleration should be taken into account in the system’s equilibrium. This aspect is investigated by treating the dynamic load as an impulse-like load. However, a realistic load needs some time to affect the whole bridge, thus the continuous change of stiffness is used to simulate the dynamic analysis. There is a lack of information on determining the value of coupling stiffness in longitudinal direction caused by a passing train. Therefore, it is important to evaluate the coupling stiffness from field measurements in order to find reliable values. The implementation of the load onto several typical bridges shows that the change of the coupling stiffness increases the stresses and it should not be neglected. The evaluation of the load due to a change of the coupling stiffness accompanied by bending of the supporting structure gives satisfactory results by using the static analysis only. Thus, a dynamic analysis can be avoided. Multiple cycles of passing trains occurring after seasonal temperature change indicate a significant increase of elastic parts along the track-bridge coupling interface and a decrease in stresses in the rails. Thus the danger of deterioration is reduced significantly Die Verwendung von durchgehend geschweißten Schienen auf Brücken führt zu zusätzlichen Längsspannungen infolge der Lastfälle jahreszeitliche Temperaturänderung, Brückendurchbiegung und Bremsen/Anfahren. Diese drei Lasten sind durch den Eurocode 1 vorgegeben und in die nationale deutsche Norm DIN Fb-101 integriert. In dieser Arbeit wird erstmals ein weiterer Lastfall identifiziert und behandelt, der durch den Wechsel der Koppelsteifigkeit in Längsrichtung zwischen Gleis und Tragwerk bei der Zugüberfahrt begründet wird. Dieser Lastfall wird hier mit „Ruck“ bezeichnet und ist eine zwangsläufige Konsequenz des nichtlinearen Längsverschiebewiderstandes, wie er im EC 1 und im DIN Fb-101 vorgegeben ist. Dennoch wurden die Auswirkungen auf das Systemverhalten bisher nicht untersucht. Bei einem Wechsel vom unbelasteten Gleis zum belasteten Gleis während einer Zugüberfahrt erhöht sich zum Beispiel der Längsverschiebewiderstand für ein Schottergleis um den Faktor 3! Die dadurch bedingte Veränderung des Zusammenwirkens zwischen Gleis und Tragwerk führt zu einer Veränderung des Systemzustandes und damit zu veränderten Schienenspannungen. Für durchgehend geschweißte Schienen spielt die Längskopplung zwischen Schiene und Brücke eine wesentliche Rolle. Beim Schottergleis wird sie dargestellt durch die Einbettung des Gleisrostes im Schotterbett im Zusammenwirken mit der Schienenbefestigung. Bei der festen Fahrbahn durch das Befestigungssystem. Für kleine Deformationen ist die Koppelsteifigkeit proportional zur Relativverschiebung zwischen Gleis und Brücke. Darüberhinaus geht das linear elastische Verhalten in ein quasi plastisches Verhalten mit konstanter Koppelkraft über. Folgerichtig ist die Behandlung einer Lastenfolge nur in inkrementeller Weise unter Einbeziehung der Verformungsgeschichte mechanisch korrekt. Die Lastfälle Bremsen/Anfahren, Brückendurchbiegung und Ruck ereignen sich nur während der Zugüberfahrt; also in relativ kurzer Zeit, dann allerdings mit einem erheblichen Lastgradienten. Somit stellt sich die Frage nach dem Einfluss der Massenbeschleunigungen, die in dieser Arbeit geklärt wird. Die im Fachbericht genanntenWerte für den Längsverschiebewiderstand des belasteten Gleises basieren auf einer relativ geringen Datenmenge. Aus diesem Grund werden die Messdaten einer umfangreichen Feldmessung mit Zugüberfahrten zu Aussagen über den Längsverschiebewiederstand herangezogen und die Problematik derartiger Messungen beleuchtet. Die unterschiedlichen Modellierungen des Lastfalls „Ruck“, einmal rein statisch und zum anderen dynamisch, ergeben übereinstimmende Schienenlängsspannungen für die statische und die kontinuierliche dynamische Variante. Somit kann auf die aufwändige dynamische Analyse verzichtet werden. Mehrere Zyklen von Zugüberfahrten im Anschluss an eine jahreszeitliche Temperaturänderung bewirken einen signifikanten Abbau der Durchrutschbereiche, also eine Erhöhung der elastischen Abschnitte in der Koppelfuge zwischen Bauwerk und Gleis verbunden mit einer Abnahme der Schienendruckspannungen. Somit hilft dieser Effekt dem System, der jahreszeitlichen Temperaturänderung zu widerstehen

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22

Widarda, Dina Rubiana. "Longitudinal forces in continuously welded rails due to nonlinear track-bridge interaction for loading sequences." Doctoral thesis, Technische Universität Dresden, 2008. https://tud.qucosa.de/id/qucosa%3A23616.

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Abstract:

The use of continuously welded rails (CWR) governs the longitudinal stress caused by seasonal temperature changes, bending of supporting structure and braking/accelerating due to passing trains. Those three loads have been regulated in Eurocode1 and accomplished by the national codes like DIN Fb-101 in Germany. An additional loading case identified and treated in this thesis is the load due to a change of the coupling stiffness in longitudinal direction between the track and bridge. This additional load occurs as a consequence of the employment of a nonlinear stiffness law which increases the restoring force by a factor of 3 when the situation of the track changes from ‘unloaded’ to ‘loaded’ due to a passing train. This particular phenomenon has not been mentioned in the codes so far though it is a natural consequence of fundamental conditions in those codes. For CWR the longitudinal coupling between the rail and bridge plays an important role. This coupling interface is created either by a ballast, for a ballasted track, or by a fastening system in the case of slab track. The deformation state of the coupling interface characterizes the behaviour of the system, whether elastic or plastic. Therefore, the nonlinear behaviour is valid for the system. To accommodate the nonlinear nature, a sequential loading analysis is used, taking into account the loading history. As the change situation due to a passing train happens in a short time, the influence of the mass acceleration should be taken into account in the system’s equilibrium. This aspect is investigated by treating the dynamic load as an impulse-like load. However, a realistic load needs some time to affect the whole bridge, thus the continuous change of stiffness is used to simulate the dynamic analysis. There is a lack of information on determining the value of coupling stiffness in longitudinal direction caused by a passing train. Therefore, it is important to evaluate the coupling stiffness from field measurements in order to find reliable values. The implementation of the load onto several typical bridges shows that the change of the coupling stiffness increases the stresses and it should not be neglected. The evaluation of the load due to a change of the coupling stiffness accompanied by bending of the supporting structure gives satisfactory results by using the static analysis only. Thus, a dynamic analysis can be avoided. Multiple cycles of passing trains occurring after seasonal temperature change indicate a significant increase of elastic parts along the track-bridge coupling interface and a decrease in stresses in the rails. Thus the danger of deterioration is reduced significantly. Die Verwendung von durchgehend geschweißten Schienen auf Brücken führt zu zusätzlichen Längsspannungen infolge der Lastfälle jahreszeitliche Temperaturänderung, Brückendurchbiegung und Bremsen/Anfahren. Diese drei Lasten sind durch den Eurocode 1 vorgegeben und in die nationale deutsche Norm DIN Fb-101 integriert. In dieser Arbeit wird erstmals ein weiterer Lastfall identifiziert und behandelt, der durch den Wechsel der Koppelsteifigkeit in Längsrichtung zwischen Gleis und Tragwerk bei der Zugüberfahrt begründet wird. Dieser Lastfall wird hier mit „Ruck“ bezeichnet und ist eine zwangsläufige Konsequenz des nichtlinearen Längsverschiebewiderstandes, wie er im EC 1 und im DIN Fb-101 vorgegeben ist. Dennoch wurden die Auswirkungen auf das Systemverhalten bisher nicht untersucht. Bei einem Wechsel vom unbelasteten Gleis zum belasteten Gleis während einer Zugüberfahrt erhöht sich zum Beispiel der Längsverschiebewiderstand für ein Schottergleis um den Faktor 3! Die dadurch bedingte Veränderung des Zusammenwirkens zwischen Gleis und Tragwerk führt zu einer Veränderung des Systemzustandes und damit zu veränderten Schienenspannungen. Für durchgehend geschweißte Schienen spielt die Längskopplung zwischen Schiene und Brücke eine wesentliche Rolle. Beim Schottergleis wird sie dargestellt durch die Einbettung des Gleisrostes im Schotterbett im Zusammenwirken mit der Schienenbefestigung. Bei der festen Fahrbahn durch das Befestigungssystem. Für kleine Deformationen ist die Koppelsteifigkeit proportional zur Relativverschiebung zwischen Gleis und Brücke. Darüberhinaus geht das linear elastische Verhalten in ein quasi plastisches Verhalten mit konstanter Koppelkraft über. Folgerichtig ist die Behandlung einer Lastenfolge nur in inkrementeller Weise unter Einbeziehung der Verformungsgeschichte mechanisch korrekt. Die Lastfälle Bremsen/Anfahren, Brückendurchbiegung und Ruck ereignen sich nur während der Zugüberfahrt; also in relativ kurzer Zeit, dann allerdings mit einem erheblichen Lastgradienten. Somit stellt sich die Frage nach dem Einfluss der Massenbeschleunigungen, die in dieser Arbeit geklärt wird. Die im Fachbericht genanntenWerte für den Längsverschiebewiderstand des belasteten Gleises basieren auf einer relativ geringen Datenmenge. Aus diesem Grund werden die Messdaten einer umfangreichen Feldmessung mit Zugüberfahrten zu Aussagen über den Längsverschiebewiederstand herangezogen und die Problematik derartiger Messungen beleuchtet. Die unterschiedlichen Modellierungen des Lastfalls „Ruck“, einmal rein statisch und zum anderen dynamisch, ergeben übereinstimmende Schienenlängsspannungen für die statische und die kontinuierliche dynamische Variante. Somit kann auf die aufwändige dynamische Analyse verzichtet werden. Mehrere Zyklen von Zugüberfahrten im Anschluss an eine jahreszeitliche Temperaturänderung bewirken einen signifikanten Abbau der Durchrutschbereiche, also eine Erhöhung der elastischen Abschnitte in der Koppelfuge zwischen Bauwerk und Gleis verbunden mit einer Abnahme der Schienendruckspannungen. Somit hilft dieser Effekt dem System, der jahreszeitlichen Temperaturänderung zu widerstehen.

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23

Rihn, Sandra. "Construction et étude de composés fluorescents à base d'unités hydroxyphényl-s-triazines et boradiazaindacènes." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01018647.

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Les travaux réalisés dans le cadre de la thèse avaient pour but la synthèse de nouveaux fluorophores basés sur les unités BODIPYs et hydroxyphényl-s-triazines. Pour être utilisées comme sondes efficaces dans des applications en chimie et en biologie, les chromophores doivent présenter une forte brillance et des rendements quantiques de fluorescence élevés, une modulation aisée de ses propriétés optiques ainsi qu'une bonne stabilité chimique et photochimique. Une stratégie originale et efficace a été développée pour l'obtention de dérivés d'o-hydroxyphényl-s-triazine. Ces derniers présentent des déplacements de Stokes anormalement élevés ayant pour origine un transfert de proton intramoléculaire ultrarapide à l'état excité (ESIPT). L'extension du système π-conjugué sur les différentes plateformes de départ a été réalisée par couplages pallado-catalysés et/ou condensation de Knoevenagel, permettant ainsi d'accéder à une large gamme spectrale en absorption et en émission. Le développement d'une nouvelle voie de synthèse à permis l'obtention d'oligo-BODIPYs par couplage oxydant réalisé en associant PIFA et un acide de Lewis. Toutes les propriétés photophysiques des nouvelles sondes ont été étudiées et ont fait l'objet de discussions détaillées.

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24

Souffrin, Agathe. "Conception, synthèse et évaluation pharmacologique de maléimides, inhibiteurs potentiels de l'intégrase du VIH-1." Thesis, Tours, 2012. http://www.theses.fr/2012TOUR3801/document.

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Notre équipe de recherche a récemment développé les premiers inhibiteurs d’une enzyme à DDE, la transposase MOS1, une enzyme analogue à l’intégrase du VIH-1. Ces molécules, de type bisfurylmaléimides, ont également montré une efficacité contre les activités enzymatiques de l’intégrase du VIH. En se basant sur ces résultats, nous avons entrepris la synthèse de nouveaux bisfurylmaléimides dans le but d’identifier de nouveaux inhibiteurs de l’intégrase et de proposer de nouvelles molécules dans la lutte contre le virus responsable du SIDA. L’originalité de notre démarche est l’utilisation de la transposase MOS1 comme modèle pour concevoir nos molécules. Les méthodologies utilisées pour accéder à ces molécules font essentiellement appel à la chimie catalysée par des métaux de transition mais aussi à des réactions de chimie hétérocyclique telles que des réactions de Mitsunobu, de Knoevenagel ou encore de Horner-Wadsworth-Emmons. L’ensemble des molécules synthétisées a fait l’objet d’une évaluation de leurs activités inhibitrices sur la transposase MOS1 et l’intégrase du VIH-1. Leurs propriétés antivirales contre le VIH ont également été évaluées. Parallèlement à ces travaux, nous nous sommes intéressés à la réactivité du noyau maléimide dans des réactions de couplage pallado-catalysées et plus particulièrement dans des couplages de Sonogashira Our research team has recently developed the first inhibitors of a DDE enzyme, MOS1 transposase, an enzyme similar to the HIV-1 integrase. These molecules, having a bisfurylmaleimide structure, also showed efficacy against enzymatic activities of HIV integrase. Based on these results, we undertook the synthesis of new bisfurylmaleimides in order to identify new integrase inhibitors and propose new molecules in the fight against the virus that causes AIDS. The originality of our approach is the use of MOS1 transposase as a model for designing our molecules. Methodologies used to access these molecules are essentially involving chemistry catalyzed by transition metals but also reactions of heterocyclic chemistry such as Mitsunobu, Knoevenagel or Horner-Wadsworth-Emmons reactions. All synthesized molecules has been evaluated for their inhibitory activities on the MOS1 transposase and HIV-1 integrase. Their antiviral properties against HIV were also evaluated. Parallel to this work, we investigated the reactivity of the maleimide core in palladium-catalyzed cross-coupling reactions especially in Sonogashira couplings

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25

Bahlmann, Arnold. "Entwicklung und Validierung eines Enzyme-linked Immunosorbent Assays (ELISA) für die Quantifizierung von Carbamazepin in Abwasser, Oberflächenwasser und Trinkwasser." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://dx.doi.org/10.18452/16729.

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Ein kompetitiver ELISA (Enzyme-linked Immunosorbent Assay) für den Nachweis von Carbamazepin (CBZ) mit einer Bestimmungsgrenze von ca. 30 ng/L wurde entwickelt und validiert. Dieser in Gewässern häufig auftretende anthropogene Marker wurde anschließend in einer Vielzahl an Proben aus Abwässern, Oberflächengewässern und Trinkwässern nachgewiesen. Der ELISA zeigte eine exzellente Präzision und erbrachte in allen Matrizes geringfügig höhere Analysenergebnisse als die Referenzmethode HPLC-MS/MS. Die beständige Überbestimmung der CBZ-Konzentration in Höhe von ca. 7 % konnte auf die Präsenz von Cetirizin und geringen Mengen des persistenten Metaboliten 10,11 Epoxy¬carbamazepin (EP-CBZ) zurückgeführt werden. Die Bindungseigenschaften des verwendeten Antikörpers wurden anhand der Kreuz¬reaktivi¬täten von 37 Substanzen eingehend untersucht. Nach Kopplung von Flüssig¬chromato¬graphie und ELISA konnte das strukturell nicht mit CBZ verwandte Anti¬histaminikum Cetirizin als Kreuzreaktand identifiziert werden. Der störende Einfluss dieses Kreuz¬reaktanden auf den CBZ-ELISA konnte nach einer Änderung des pH-Wertes im Proben¬puffer minimiert werden. Die pH-abhängige Selektivitätssteuerung ermöglichte überdies die Entwicklung eines Dual-Analyt-Immunoassays für die parallele Bestimmung von CBZ und Cetirizin. Darüber hinaus wurden die Metaboliten EP-CBZ, DiOH-CBZ, 2-OH-CBZ, 3-OH-CBZ und 10 OH-CBZ in Abwasser, Oberflächenwasser und Trinkwasser quantifiziert. DiOH-CBZ erwies sich als ähnlich persistent wie CBZ und wurde in besonders hohen Konzentrationen gefunden. Außerdem wurden mehrere weitere bislang nicht identifizierte Abbauprodukte von CBZ gefunden. Da weder Probenvorbereitung noch Probenanreicherung erforderlich sind, ist der Test schnell und kostengünstig durchführbar. Die für den Test nötigen Probenvolumen sind mit weniger als 1 mL sehr gering. Diese Eigenschaften erlauben ein Hochdurchsatzscreening und machen die Methode interessant für den Einsatz im Gewässermonitoring. A competitive ELISA (enzyme-linked immunosorbent assay) for the quantitation of carbamazepine (CBZ) was developed and validated. A limit of quantitation (LOQ) of ca. 30 ng/L allowed for the quantitation of CBZ in many samples from wastewater, surface water and drinking water. The method was found to be excellently precise, but it displayed slightly higher results than obtained by the reference method liquid chromatography-tandem mass spectrometry (LC-MS/MS). The nearly constant overestimation of 7 % could be attributed to the presence of small amounts of cetirizine and the persistent metabolite 10,11 epoxy¬carbamazepine (EP-CBZ). The binding properties of the antibody were studied by determining the cross-reactivities of 37 compounds. Hyphenating liquid chromatography to ELISA led to the discovery of the cross-reactive antihistamine cetirizine that shares no obvious structural similarity with CBZ. The bias caused by cetirizine was eliminated by changing the pH value of the sample buffer. Moreover, the antibody’s pH-dependent selectivity enabled a dual-analyte immunoassay for the parallel determination of CBZ and cetirizine. Furthermore, the metabolites EP-CBZ, DiOH-CBZ, 2-OH-CBZ, 3-OH-CBZ and 10-OH-CBZ were quantified in wastewater, surface water and drinking water. DiOH-CBZ showed the highest concentrations of all analaytes investigated and was found to be equally persistent as CBZ. In addition, several further degradation products of CBZ were found that could not be identified. The ELISA allowed the detection of diurnal and seasonal fluctuations of analyte concentrations in wastewater and surface water. The anthropogenic marker CBZ enabled to trace wastewater from the source to the receiving waters. Since neither sample pretreatment nor enrichment is necessary, the method is very fast and cost-effective. Only a small sample volume (less than 1 mL) is needed making this ELISA an appropriate high-throughput screening tool for environmental monitoring.

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26

Khan, Abdulaziz M. "Kinetic Studies of Oxidative Coupling of Methane Reaction on Model Catalysts." Thesis, 2016. http://hdl.handle.net/10754/609454.

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With the increasing production of natural gas as a result of the advancement in the technology, methane conversion to more valuable products has become a must. One of the most attractive processes which allow the utilization of the world’s most abundant hydrocarbon is the oxidative coupling. The main advantage of this process is the ability of converting methane into higher paraffins and olefins (primarily C2) in a direct way using a single reactor. Nevertheless, low C2+ yields have prevented the process to be commercialized despite the fact that great number of attempts to prepare catalysts were conducted so that it can be economically viable. Due to these limitations, understanding the mechanism and kinetics of the reaction can be utilized in improving the catalysts’ performance. The reaction involves the formation of methyl radicals that undergo gas-phase radical reactions. CH4 activation is believed to be done the surface oxygen species. However, recent studies showed that, in addition to the surface oxygen mediated pathway, an OH radical mediated pathway have a large contribution on the CH4 activation. The experiments of Li/MgO, Sr/La2O3 and NaWO4/SiO2 catalysts revealed variation of behavior in activity and selectivity. In addition, water effect analysis showed that Li/MgO deactivate at the presence of water due to sintering phenomena and the loss of active sites. On the other hand, negative effect on the C2 yield and CH4 conversion rate was observed with Sr/La2O3 with increasing the water partial pressure. Na2WO4/SiO2 showed a positive behavior with water in terms of CH4 conversion and C2 yield. In addition, the increment in CH4 conversion rate was found to be proportional with PO2 ¼ PH2O ½ which is consistent with the formation of OH radicals and the OH-mediated pathway. Experiments of using ring-dye laser, which is used to detect OH in combustion experiments, were tried in order to detect OH radicals in the gas-phase of the catalyst. Nevertheless, noisy signals were obtained that prevented the ability of detecting OH at the expected few ppms concentrations. Further optimization of the experimental setup is required.

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27

Liu, Ching-Fang, and 劉靜芳. "Coupling photoelectrochemical catalysis and photoelectrochemical Fenton process for the treatment of dye industrial wastewater." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/26227799481044786150.

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博士 國立交通大學 環境工程系所 104 In recent years, advanced oxidation techniques including electrochemical advanced oxidation processes (EAOP) have gained much attention. EAOP have been employed widely for the decontamination of wastewaters containing high-strength organic pollutants due to their versatility, high efficiency, and environmental compatibility. The effectiveness of EAOP such as photoelectrochemical catalysis (PEC), electro-Fenton (EF) and photoelectro-Fenton (PEF) are ascribed to the generation of hydroxyl radicals (OH•), which has a high redox potential that can react non-selectively with most organic compounds to produce CO2, water, and inorganic ions. Recently, many coupled and hybrid electrochemical processes have been proposed aiming developing more powerful processes for dyes removal. It provides more advantages than individual electrochemical processes owing to the high degradation performance on the treatment of wastewater via combined different electrochemical methods. Therefore, the purpose of this thesis was to develop the coupled PEC/PEF process by combining TiO2/Ti and stainless steel dual anode system. In the first parts of this study, the TiO2/Ti and stainless steel anodes would be integrated individually. After that, the combining both anodes with coupled PEC/PEF process for treatment of dye wastewater treatment was integrated in the second part of this study. The first part was the integration of TiO2/Ti photoanode, the TiO2/Ti photoanode was prepared by electrophoretic deposition (EPD) process. The performance of TiO2/Ti photoanode was tested by degradation of azo dye Orange G (OG) using a PEC system. Results of surface analysis and electrochemical analysis revealed that the optimal EPD condition was a deposition potential of 180 V for 1 min and annealed at 350oC. These results showed that the coupling effect of photocatalytic and electrochemical oxidation processes was evaluated in terms of the decolorization of OG. The degradation of OG increased in the following increasing order: photocatalysis (PC) < electrochemical oxidation (EO) < PEC. The degradation of OG follows the pseudo first-order kinetic in PEC process, which proposed the OH radical is the major player in the decolorization reaction. The second part was the integration of stainless steel (SS) anode and graphite cathode system with EF and PEF processes. In this system, the ferrous ions being derived from a sacrificial stainless steel anode and hydrogen peroxide being produced at a graphite cathode. Results indicated that the applied current controlled the rate of electrogeneration of ferrous ion and hydrogen peroxide. The optimal [H2O2]/[Fe2+] (molar) ratio was 3.58 at an applied current density of 45 uA/cm2 for the SS-graphite system. The OG degradation efficiency in the PEF process was greater than that of the EF process under otherwise identical conditions. At an applied current density of 45 uA/cm2, stainless steel anode achieved a decolorization of 85% after 3 h. The degradation of OG followed the pseudo first-order kinetics for both EF and PEF processes, which proposed that OH radical was a main species for the decolorization reaction. For coupling the PEC and PEF two processes, the dual anode electrochemical system by combining the TiO2/Ti and stainless steel was developed for OG treatment. From the result of kinetic aspect, the efficiency of the PEC/PEF process depended on the Fe2+ and H2O2 electrogeneration which yielded OH radical in the solution bulk, which could promote the oxidative degradation of OG and its byproducts. The degradation of OG increased in the following increasing order: photocatalysis < electrochemical oxidation < photoelectrochemical degradation < electro-Fenton < photoelectro-Fenton < coupling the photoelechemical and photoelectro-Fenton. After the 7 h reaction time, a decolorization of 99.8% and TOC removal of 70% were achieved at an applied current density of TiO2/Ti and stainless steel anodes were 75 uA/cm2 and 45 uA/cm2. The degradation of OG following the pseudo first-order kinetic for PEC/PEF process.

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28

ZIDELL, ROBERT HARRY. "DEVELOPMENT AND CHARACTERIZATION OF A DYE-COUPLING ASSAY TO STUDY GAP JUNCTIONAL COMMUNICATION IN SMOOTH MUSCLE CELLS." 1989. http://books.google.com/books?id=I3o9AAAAMAAJ.

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29

li, Siao-Wun, and 李曉雯. "Study of Two-Beam Coupling Effects Induced By the Polarization Grating in Azo-Dye-Doped Nematic Liquid Crystals." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/82007464301175493187.

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碩士 國立成功大學 物理學系碩博士班 94 This thesis studies the orientational photorefractive (PR) effect induced by a polarization grating (PG) in an azo-dye-doped liquid crystal (ADDLC) film. The PG-PR effect is induced by applying a dc field together with an interfering field created by two mutually orthogonal circularly polarized beams simultaneously. The cause of the PG-PR effect is due to the anisotropy of azo-dye to the polarization of a pump beam. Two-beam coupling(TBC) is one featured result from orientational photorefractive (PR) effect. In this thesis, we study how the applied voltage, beam power ratio and total pump beam intensity effect the gain constant in the TBC effect. Four conclusions can be drawn from the experimental results. (1) When the applied dc voltage is on(off), the TBC effect shows up(off). (2) The power ratio of the two pump beams affects the TBC effects significantly. It is found that the coupling gain constant increasing with the power ratio. (3) The coupling gain constant is initial increasing with the magnitude of the applied voltage. It is peaked at ~2.6V, and then decreasing with further increase of the voltage. (4) The total pump-beam intensity is found to affect the coupling gain constant effectively. Similarly to above(3), it is increasing with the total pump-beam intensity, and peaks at ~44.8mW/cm2, and finally decreases with further increase of the pump-beam intensity.

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30

he, shin-shian, and 何信憲. "Study on the Glass Fiber after Pre-treating with Silane Coupling Agent and Dying by Acid Dye Stuff." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/70787892366907240686.

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碩士 逢甲大學 纖維與複合材料學系 99 Glass fiber to retain the characteristics of the glass, such as thermal stability, quality of electrical insulation, chemical stability and on the human body, the environment without adversely affecting, to apply fibrosis and to obtain the physical properties of high strength. Glass and other kinds of high strength fiber compared to its strength, Tensile Strength、elongation rate and elasticity rate of more balanced, Its very suitable for composite materials reinforced material. But, there is unable dye of the glass fiber defects. Acid dyes can be dyeing wool in acidic、neutral dye bath. In terms of the chemical structure, such dye is a sodium salt form of pigment acid, or for the heavy metal salt forms of the anion dye. In addition to acid dye dyeing wool、silk, nylon、polyurethanes , it can be used for leather, paper and synthetic resin of the coloring, and for food coloring. Therefore, the purpose of this study is to improve the shortcomings of stained glass can not be used , the use of silane coupling agent when combined with the glass fiber and then to dying for acid dyes, so that today''s glass fiber products can make a variety of color changes and meet the people''s visual experience,by the experimental result knew, in pH3 dyes in the bath, the dye strength is 3% o.m.f., by 50℃ holds warm 90 min, and after etching treatment dyes the glass fiber has the best dyeability.

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31

Forker, Roman. "Electronic Coupling Effects and Charge Transfer between Organic Molecules and Metal Surfaces." Doctoral thesis, 2009. https://tud.qucosa.de/id/qucosa%3A24145.

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We employ a variant of optical absorption spectroscopy, namely in situ differential reflectance spectroscopy (DRS), for an analysis of the structure-properties relations of thin epitaxial organic films. Clear correlations between the spectra and the differently intense coupling to the respective substrates are found. While rather broad and almost structureless spectra are obtained for a quaterrylene (QT) monolayer on Au(111), the spectral shape resembles that of isolated molecules when QT is grown on graphite. We even achieve an efficient electronic decoupling from the subjacent Au(111) by inserting an atomically thin organic spacer layer consisting of hexa-peri-hexabenzocoronene (HBC) with a noticeably dissimilar electronic behavior. These observations are further consolidated by a systematic variation of the metal substrate (Au, Ag, and Al), ranging from inert to rather reactive. For this purpose, 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) is chosen to ensure comparability of the molecular film structures on the different metals, and also because its electronic alignment on various metal surfaces has previously been studied with great intensity. We present evidence for ionized PTCDA at several interfaces and propose the charge transfer to be related to the electronic level alignment governed by interface dipole formation on the respective metals. Zur Analyse der Struktur-Eigenschafts-Beziehungen dünner, epitaktischer Molekülfilme wird in situ differentielle Reflexionsspektroskopie (DRS) als Variante der optischen Absorptionsspektroskopie verwendet. Klare Zusammenhänge zwischen den Spektren und der unterschiedlich starken Kopplung zum jeweiligen Substrat werden gefunden. Während man breite und beinahe unstrukturierte Spektren für eine Quaterrylen (QT) Monolage auf Au(111) erhält, ist die spektrale Form von auf Graphit abgeschiedenem QT ähnlich der isolierter Moleküle. Durch Einfügen einer atomar dünnen organischen Zwischenschicht bestehend aus Hexa-peri-hexabenzocoronen (HBC) mit einem deutlich unterschiedlichen elektronischen Verhalten gelingt sogar eine effiziente elektronische Entkopplung vom darunter liegenden Au(111). Diese Ergebnisse werden durch systematische Variation der Metallsubstrate (Au, Ag und Al), welche von inert bis sehr reaktiv reichen, untermauert. Zu diesem Zweck wird 3,4,9,10-Perylentetracarbonsäuredianhydrid (PTCDA) gewählt, um Vergleichbarkeit der molekularen Filmstrukturen zu gewährleisten, und weil dessen elektronische Anordnung auf verschiedenen Metalloberflächen bereits eingehend untersucht worden ist. Wir weisen ionisiertes PTCDA an einigen dieser Grenzflächen nach und schlagen vor, dass der Ladungsübergang mit der elektronischen Niveauanpassung zusammenhängt, welche mit der Ausbildung von Grenzflächendipolen auf den entsprechenden Metallen einhergeht.

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Ciou, Yan-Syun, та 邱彥勛. "Cross-Dehydrogenative Coupling (CDC) as Key-Transformations to Various D-π-A Organic Dyes: C-H/C-H Synthetic Study and Dye-Sensitized Solar Cells Applications". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/r4bmzd.

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碩士 國立中央大學 化學工程與材料工程學系 104 Palladium-catalyzed cross-dehydrogenative coupling between donor and acceptor-type molecules was developed for the first time to construct organic donor-π-linker-acceptor (D-π-A) dyes in the presence of pyridine and Cu(OAc)2. The advantages of this reaction are its high reaction efficiency, high regioselectivities, excellent functional group tolerance, and synthetic simplicity from the omission of the pre-functionalization. The features of this protocol make it an ideal strategy for synthesizing D-π-A dyes of interest in dye-sensitized solar cells (DSSCs). Through our methodology, three new sensitizers (CYL-8, CYL-9, and CYL-10) were prepared and employed to fabricate DSSCs. The photovoltaic characterization of the devices affords a Voc of 0.62-0.68 V, a Jsc of 5.51-10.10 mA/cm2, and a FF of 62.5-73.9 %, which correspond to an overall power conversion efficiency of 2.25-4.85 %. Our aim of presenting this method was to provide practical and step-saving access to various of D-π-A-type molecules for photovoltaic applications.

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Alturkistani, Sultan H. "Optimization of Process Variables for Oxidative Coupling of Methane." Thesis, 2019. http://hdl.handle.net/10754/652866.

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Oxidative coupling of methane (OCM) is a promising route for converting abundant natural gas resources into more useful chemicals like paraffins and olefins (primarily C2). However, to date, there is no current OCM production plant due to low overall conversion and selectivity to the desired product(s). In this work, different operating factors are studied experimentally and through simulation with respect mainly to three responses: CH4 conversion, C2 main product selectivity, and COx side product selectivity. The aim is to identify the best operating condition for maximum ethylene production combined with COx production. Design of experiments (DoE) method was used to analyze the experimental results by applying the full factorial approach. Simulation results were studied by finding the correlation strength between input factors and responses. It was found that the performance of an OCM reactor could be greatly improved under optimal operating conditions. Operating temperature and CH4/O2 ratio have the highest influence while catalyst weight and flow rate have the lowest influence on the OCM responses and mainly depend on rector dimensions.

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Barber, Frederick Lee. "Vibration problems of rotating machinery due to coupling misalignments." Thesis, 1988. http://hdl.handle.net/10945/23444.

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Vibrational analysis of rotating machinery is able to identify a large number of system ills. Shaft bow, shaft unbalance and coupling misalignments make up the major portion of the observed vibrational frequency spectra of rotating machinery. These vibrational spectra can be used to determine the type of rotating system abnormality, the degree of misalignment and the rate of alignment degradation. The proper joining of rotating machinery is a critical issue with high power and a high speed equipments. Couplings used to join machinery have a broad spectrum of characteristics and specific purposes. Couplings are used to compensate for axial, lateral and angular misalignments. In addition, couplings may exhibit constant or non-constant input versus output speed relationships. The importance of mating a driving and driven piece of equipment with the properly designed coupling is paramount. In the following report the author discusses numerous types of couplings, the behavioral characteristics of couplings and the considerations which must be taken into account when selecting a coupling for a rotating system. The analysis which follows list the various alignment discrepancies which can be detected by vibrational analysis and the requirements for non-constant and constant velocity characteristics of couplings. In addition, numerous types of couplings are catalogued and discussed. Theses. (FR)

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"Intimate Coupled Photocatalysis and Biodegradation on a Novel TiO2-Coated Biofilm Carrier." Master's thesis, 2011. http://hdl.handle.net/2286/R.I.9333.

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abstract: Intimate coupling of Ti2 photocatalysis and biodegradation (ICPB) offers potential for degrading biorecalcitrant and toxic organic compounds much better than possible with conventional wastewater treatments. This study reports on using a novel sponge-type, Ti2-coated biofilm carrier that shows significant adherence of Ti2 to its exterior and the ability to accumulate biomass in its interior (protected from UV light and free radicals). First, this carrier was tested for ICPB in a continuous-flow photocatalytic circulating-bed biofilm reactor (PCBBR) to mineralize biorecalcitrant organic: 2,4,5-trichlorophenol (TCP). Four mechanisms possibly acting of ICPB were tested separately: TCP adsorption, UV photolysis/photocatalysis, and biodegradation. The carrier exhibited strong TCP adsorption, while photolysis was negligible. Photocatalysis produced TCP-degradation products that could be mineralized and the strong adsorption of TCP to the carrier enhanced biodegradation by relieving toxicity. Validating the ICPB concept, biofilm was protected inside the carriers from UV light and free radicals. ICPB significantly lowered the diversity of the bacterial community, but five genera known to biodegrade chlorinated phenols were markedly enriched. Secondly, decolorization and mineralization of reactive dyes by ICPB were investigated on a refined Ti2-coated biofilm carrier in a PCBBR. Two typical reactive dyes: Reactive Black 5 (RB5) and Reactive Yellow 86 (RY86), showed similar first-order kinetics when being photocatalytically decolorized at low pH (~4-5), which was inhibited at neutral pH in the presence of phosphate or carbonate buffer, presumably due to electrostatic repulsion from negatively charged surface sites on Ti2, radical scavenging by phosphate or carbonate, or both. In the PCBBR, photocatalysis alone with Ti2-coated carriers could remove RB5 and COD by 97% and 47%, respectively. Addition of biofilm inside macroporous carriers maintained a similar RB5 removal efficiency, but COD removal increased to 65%, which is evidence of ICPB despite the low pH. A proposed ICPB pathway for RB5 suggests that a major intermediate, a naphthol derivative, was responsible for most of the residual COD. Finally, three low-temperature sintering methods, called O, D and DN, were compared based on photocatalytic efficiency and Ti2 adherence. The DN method had the best Ti2-coating properties and was a successful carrier for ICPB of RB5 in a PCBBR. Dissertation/Thesis M.S. Biological Design 2011

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Adluri, Sirisha. "Contributions to substrate noise due to supply coupling and pin parasitics." Thesis, 2003. http://hdl.handle.net/1957/29861.

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Thompson, Janene. "Coupling dyes to chicken IgY antibodies for the development of immunodiagnostic tests." Thesis, 2003. http://hdl.handle.net/10413/5594.

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The aim of this study was to develop a highly simplified, sensitive and specific malarial diagnostic test at the lowest possible cost. Initial work and optimisation of procedures was achieved with chicken antibodies by covalently attaching commercially available dye to them. Chicken antibodies were easily isolated from egg yolk and dye is cheap, easily visible and requires no equipment for identification of results. A dipstick dye-immunoassay was developed with nitrocellulose as the capture phase. The dye-immunoassay is an alternative to the traditional enzyme linked immunosorbent assay (ELISA) technique, which employs the use of an enzyme-substrate reaction. Numerous dyes were investigated and included Reactive black 5, trypan blue, Cibacron Blue, Congo red, Acid-black 2, dianix blue, dianix red, para-nitroaniline and primulin. Most of these dyes have dark colours which are essential for good contrast on nitrocellulose and in a microtitre plate. Some dyes contain amino (NH2) groups, which are targeted in a covalent linking step and attached to the lysine residues on antibody molecules or to the carbohydrate groups on antibody molecules. Attachment of dye molecules to antibodies with glutaraldehyde was the chief coupling method explored and conditions were optimized in this study. Unbound dye was removed by dialysis. Reactive black 5 is sensitive down to 50 nanograms of antigen on nitrocellulose. A second covalent coupling method was investigated by means of attaching dye to the carbohydrate moieties on the antibody. Reactive black 5 was sensitive down to 50 nanograms of antigen. The carbohydrate method appears to be more sensitive than the glutaraldehyde method at lower antibody concentrations. Primulin, a yellow dye, was similarly investigated. This dye does not have a dark colour initially, but can be diazotized to change its colour to orange or purple. It also fluoresces under ultra-violet light. This dye was sensitive down to 500 nanograms of antigen with both the glutaraldehyde and carbohydrate coupling techniques. A dye-linked immunosorbent assay (D-LlSA) protocol for direct antigen detection has been developed whereby the dye-antibody solution (dianix blue dye) acts as the primary antibody and substrate respectively. Sensitivity levels compare with traditional ELISAs. Dianix blue is sensitive down to 25 nanograms of antigen in a microtitre plate. Unique protein staining abilities of the dyes used in this study were indicated by staining IgY in electrophoretic gels. Acid-black 2 indicated better protein staining abilities than that of Coomassie brilliant blue. Evidence shows that dye was successfully covalently attached to antibodies and that antigen detection is possible by visualising the dye developed spots. Although malarial antibodies were not used, all procedures with chicken antibodies were optimised. Highly simplified, sensitive and specific diagnostic tests were developed. Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

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Bialas, David. "Exciton Coupling in Homo- and Heterostacks of Merocyanine and Perylene Bisimide Dyes." Doctoral thesis, 2017. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-152418.

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In the present thesis it could be demonstrated that strong exciton coupling does not only occur between same type of chromophores but also between chromophores with different excited state energies. The coupling significantly influences the optical absorption properties of the heterostacks comprising merocyanine and perylene bisimide dyes, respectively, and is an indication for coherent energy transfer between the chromophores. In addition, bis(merocyanine)-C60 conjugates have been synthesized, which self-assemble in non-polar solvents resulting in well-defined supramolecular p/n-heterojunctions in solution. These model systems enabled femtosecond transient absorption studies on the photoinduced electron transfer process, which is a key step for the formation of charge carriers in organic solar cells In der vorliegenden Doktorarbeit konnte gezeigt werden, dass eine starke Exzitonenkopplung nicht nur zwischen gleichen Chromophoren, sondern auch zwischen Chromophoren mit unterschiedlichen Energien der angeregten Zustände möglich ist. Diese beeinflusst maßgeblich die Absorptionsspektren der Heterostapel bestehend aus Merocyanin- bzw. Perylenbisimidfarbstoffen und deutet außerdem auf einen kohärenten Energientransfer zwischen den Chromophoren hin. Weiterhin wurden Bis(merocyanin)-C60-Konjugate synthetisiert, die in unpolaren Lösungsmitteln selbst assemblieren und auf diese Weise wohldefinierte supramolekulare p/n-Heterogrenzflächen gebildet werden. An diesen wurde mithilfe von femtosekundenaufgelöster transienter Absorptionsspektroskopie der photoinduzierte Elektronentransfer untersucht, was ein wichtiger Schritt bei der Erzeugung von Ladungsträgern in organischen Solarzellen darstellt

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Douglass, Julian J. "Analytic modelling of the deformation due to plate coupling at subduction zones." Thesis, 1995. http://hdl.handle.net/2429/4158.

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A majority of the largest earthquakes result from the build-up of coupling stresses between tectonic plates at subduction zones. These earthquakes arise, periodically, when the accumulating stress reaches a level which exceeds the rupture strength of the interface. The stresses along the interface may be inferred from geodetic observations obtained at the Earth's surface. The process of strain accumulation along subduction boundaries is of particular interest due to the hazard associated with great earthquakes. Hence, a significant set of geodetic data has been obtained above subduction zones. However, successful interpretation of this data for the magnitude and distribution of stress along the interface requires that a suitable physical model of the strain accumulation process be available. Here, two approaches to this modelling problem are considered. The first is a kinematic approach to the problem in which dislocation theory is used to represent the stick-slip cycle. According to this representation, the deformation due to locking is constrained by the kinematics of plate convergence, with the most important parameter being the plate convergence rate. Hence, an assumption implicit to models that are based on this representation is that the dynamics of subduction can be physically represented by a model constrained only by kinematic parameters. To evaluate this assumption, model solutions are calculated for the case of an infinite half-space Earth. New analytic expressions are derived for this case which allow for calculation of the stress distribution over the complete half-space. The model solutions reveal a subsurface stress field which is difficult to justify on physical grounds. These difficulties raise questions regarding previous interpretations of geodetic data which were based on this model. By exclusively using this model, other possible dynamic scenarios, other than that which is prescribed by the kinematic approach, are excluded from consideration by the interpreter. Given the limitations of the dislocation represention, a second, alternative approach to the problem is proposed. This approach is based on a dynamic representation of the process of strain build-up. The overthrust wedge is treated as a free body with tractions applied along its surface. The deformation is then calculated for a prescribed distribution of force along the plate interface. A uniform elastic rheology is assumed. Thus, the fundamental elasticity problem to be solved is that of an infinite elastic wedge subjected to traction boundary conditions. Solutions are obtained by two different, but complementary techniques. In the first, the wedge is conformally mapped to an infinite strip and solutions obtained by Fourier transform methods. Equivalent solutions are also obtained by applying the Mellin transform directly to the biharmonic equation for the Airy stress function. The results of these calculations show that entirely different distributions of basal tractions can lead to very similar deformation signals along the top surface of the wedge. Thus, an ambiguity in the interpretation of the geodetic data is confirmed which is not accounted for in deformation predictions based on the dislocation approach.

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Pohl, M. B., and John G. Buckley. "Changes in foot and shank coupling due to alterations in foot strike pattern during running." 2007. http://hdl.handle.net/10454/15848.

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No The purpose of this article is determining if and how the kinematic relationship between adjacent body segments changes when an individual’s gait pattern is experimentally manipulated can yield insight into the robustness of the kinematic coupling across the associated joint(s). The aim of this study was to assess the effects on the kinematic coupling between the forefoot, rearfoot and shank during ground contact of running with alteration in foot strike pattern. Twelve subjects ran over-ground using three different foot strike patterns (heel strike, forefoot strike, toe running). Kinematic data were collected of the forefoot, rearfoot and shank, which were modelled as rigid segments. Coupling at the ankle-complex and midfoot joints was assessed using cross-correlation and vector coding techniques. In general good coupling was found between rearfoot frontal plane motion and transverse plane shank rotation regardless of foot strike pattern. Forefoot motion was also strongly coupled with rearfoot frontal plane motion. Subtle differences were noted in the amount of rearfoot eversion transferred into shank internal rotation in the first 10–15% of stance during heel strike running compared to forefoot and toe running, and this was accompanied by small alterations in forefoot kinematics. These findings indicate that during ground contact in running there is strong coupling between the rearfoot and shank via the action of the joints in the ankle-complex. In addition, there was good coupling of both sagittal and transverse plane forefoot with rearfoot frontal plane motion via the action of the midfoot joints.

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gu-wei, Lin, and 林谷韋. "Numerical analysis on natural coupling between fluid and structure due to vortex-induced vibration." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/04287888051629014195.

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Pohl, M. B., N. Messenger, and John G. Buckley. "Changes in foot and lower limb coupling due to systematic variations in step width." 2005. http://hdl.handle.net/10454/15849.

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No Motion at the midfoot joints can contribute significantly to overall foot motion during gait. However, there is little information regarding the kinematic coupling relationship at the midfoot. The purpose of the present study was to determine whether the coupling relationship at the midfoot and subtalar joints was affected when step width was manipulated during running. Twelve subjects ran over-ground at self-selected speeds using three different step widths (normal, wide, cross-over). Coupling at the midfoot (forefoot relative to rearfoot) and subtalar (rearfoot relative to shank) joints was assessed using cross-correlation techniques. Rearfoot kinematics were significantly different from normal running in cross-over running (P < 0.05) but not in wide running. However, coupling between rearfoot eversion/inversion and shank rotation was consistently high (r > 0.917), regardless of step width. This was also the case for coupling between rearfoot frontal plane motion and forefoot sagittal plane (r < 0.852) and forefoot transverse plane (r > 0.946) motion. There was little evidence of coupling between rearfoot frontal plane motion and forefoot frontal plane motion in any of the conditions. Forefoot frontal plane motion appeared to have little effect on rearfoot frontal plane motion and thus, had no effect on motion at the subtalar joint. The strong coupling of forefoot sagittal and transverse plane motions with rearfoot frontal plane motion suggests that forefoot motion exerts an important influence on subtalar joint kinematics.

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Liess, Andreas. "Structure-Property Relationships of Merocyanine Dyes in the Solid State: Charge Transport and Exciton Coupling." Doctoral thesis, 2017. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-152900.

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The present thesis demonstrates the importance of the solid state packing of dipolar merocyanine dyes with regard to charge transport and exciton coupling. Due to the charge transport theory for disordered materials, it is expected that high ground state dipole moments in amorphous thin films lead to low mobility values due to a broadening of the density of states. However, due to their inherent dipolarity, merocyanine dyes usually align in antiparallel dimers in an ordered fashion. The examination of twenty different molecules with ground state dipole moments up to 15.0 D shows that by a high dipolarity and well-defined sterics, the molecules pack in a highly regular two-dimensional brickwork-type structure, which is beneficial for hole transport. Utilization of these molecules for organic thin-film transistors (OTFTs) leads to hole mobility values up to 0.21 cm²/Vs. By fabrication of single crystal field-effect transistors (SCFETs) for the derivative showing the highest mobility values in OTFTs, even hole mobilities up to 2.34 cm²/Vs are achieved. Hence, merocyanine based transistors show hole mobility values comparable to those of conventional p-type organic semiconductors and therefore high ground state dipole moments are not necessarily disadvantageous regarding high mobility applications. By examination of a different series of ten merocyanine dyes with the same chromophore backbone but different donor substituents, it is demonstrated that the size of the donor has a significant influence on the optical properties of thin films. For small and rigid donor substituents, a hypsochromic shift of the absorption compared to the monomer absorption in solution is observed due to the card stack like packing of the molecules in the solid state. By utilization of sterical demanding or flexible donor substituents, a zig-zag type packing is observed, leading to a bathochromical shift of the absorption. These packing motifs and spectral shifts with an offset of 0.93 eV of the H- and J-bands comply with the archetype examples of H- and J-aggregates from Kasha’s exciton theory Im Rahmen der vorliegenden Doktorarbeit wird die Wichtigkeit der Packung von dipolaren Merocyaninfarbstoffen im Festkörper im Hinblick auf Ladungstransport sowie Exzitonenkopplung demonstriert. Aufgrund der Ladungstransporttheorie für ungeordnete Materialien wird erwartet, dass hohe Grundzustandsdipolmomente die Mobilität aufgrund einer Verbreiterung der Zustandsdichte verringern. Allerdings neigen Merocyanine durch ihre Dipolarität normalerweise zur Ausbildung von geordneten antiparallelen Dimeren. Durch Untersuchung von zwanzig verschiedenen Molekülen mit Grundzustandsdipolmomenten bis zu 15.0 D wird gezeigt, dass durch eine hohe Dipolarität sowie eine gut definierte Sterik der Moleküle eine hoch geordnete zweidimensionale Backstein-artige Packung erzielt wird, welche günstig für den Lochtransport ist. Hierdurch werden in organischen Dünnschichttransistoren (OTFTs) Lochmobilitäten bis zu 0.21 cm²/Vs erzielt. Durch Fertigung von Einkristallfeldeffekttransistoren (SCFETs) für das Derivat mit den höchsten Lochmobilitäten in OTFTs werden außerdem Lochmobilitäten bis zu 2.34 cm²/Vs demonstriert. Damit zeigen Merocyanin-basierte Transistoren ähnliche Lochmobilitätswerte wie konventionelle organische p-Halbleiter. Folglich sind hohe Grundzustandsdipolmomente für Anwendungen, welche hohe Mobilitäten erfordern, nicht zwangsläufig von Nachteil. Durch Untersuchung einer weiteren Serie von zehn Merocyaninfarbstoffen mit gleichem Chromophorgrundgerüst und verschiedenen Donorsubstituenten wird außerdem gezeigt, dass die Größe des Donors einen signifikanten Einfluss auf die optischen Eigenschaften von Dünnschichten hat. Für kleine und rigide Donorsubstituenten wird eine hypsochrome Verschiebung der Absorption im Vergleich zum Monomer in Lösung beobachtet, welche durch eine Kartenstapel-artige Packung der Farbstoffe im Festkörper bedingt wird. Bei der Verwendung von sterisch anspruchsvollen oder flexiblen Donorsubstituenten wird eine Zick-Zack-artige Packung beobachtet, welche eine bathochrome Verschiebung der Absorption bewirkt. Diese Packungsmotive und spektralen Verschiebungen mit einem Versatz von 0.93 eV der H- und J-Banden stehen im Einklang zu den typischen Beispielen von H- und J-Aggregaten aus Kashas Exzitonentheorie

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Chiang, Yu-Cheng, and 江育誠. "Study of Two-State Current Phenomenon due to Neighboring-Device Coupling Effect in MIS(p) Tunnel Diode." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7g4bx9.

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碩士 國立臺灣大學 電子工程學研究所 107 In this thesis, the two-state phenomenon in current behavior of coupled MIS device with SiO2 as dielectric material is investigated. The coupled MIS device is separated to two parts. One is the inner circle MIS tunnel diode called Sensor MIS, and the other is outside ring MIS tunnel diode called Storage MIS. By giving a negative stress on Storage MIS the Sensor MIS will read a lower current level, and by giving a positive stress on Storage MIS the Sensor MIS will read a higher current level. In chapter 2, the overview of the two-state current phenomenon is shown by two-state current window and retention characteristic. The mechanism of this phenomenon is analyzed by the capacitance-voltage characteristic of outside MIS tunnel diode after set and reset. It can be found that the trapped electrons play an important role in the two-state phenomenon. The electron trapping situation in Storage MIS will affect the Sensor MIS read current situation because of lateral coupling effect. Although the trapped electrons are very few, the current is very sensitive to the effective Schottky barrier. The read current will show a current on/off ratio with two or more order. The inference of this mechanism is further discussed with coupled devices with different gap space between Sensor and Storage MIS. The CV characteristics between the two devices show different coupling effects, and the different coupling effects will affect the two-state current behaviors of the two devices. In chapter 3, the relationship between oxide thickness and two-state current behavior of coupled MIS device is further investigated. It is found that device with thicker oxide will show a larger on/off current window, but a worse retention characteristic. This is a trade-off between current window and retention characteristic. The read voltage of Sensor MIS also affects the current window, and we suggest that the best choice of read voltage is the saturation voltage of the Sensor MIS.

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Lin, Chunchi, and 林崇致. "Design and characterization of near-infrared organic dyes coupling to silicon ring microcavity and silicon photonic crystal nanocavity." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/16003265843197908959.

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碩士 國立清華大學 光電工程研究所 103 In recently years, the semiconductor process technology have a substantial advances; however, it still suffer the physical limit of material. For reach the Moore’s law, the advances of integrated optics is the key subject. The resonant cavities are the essential elements in the integrated optics. Here we select the near-infrared organic laser dye IR-26 to be the gain medium, then measure and design the resonant cavity which its resonance wavelength at 1310 nm. The characteristic of slot ring microcavity have been measured to assess the probability of combination with IR-26. Then we optimize the slot ring structure and design the better measurement to collect the data. Based on the slot ring mucrocavity’s result, we further design the photonic crystal nanocavity. Here we utilize the finite-difference time-domain to simulate the 2-D photonic crystal slab nanocavity on the silicon on insulator, and the design resonant wavelength at 1310 nm. By adjusting the air hole around the cavity and adding a slot in cavity center, we optimize the cavity’s quality factor and mode volume, enhance its light-matter interaction. For increasing the vertical emission efficiency, the extra cyclical changes be added on the structure around the cavity to transform the far-field profile. It’s also mean the vertical coupling efficiency be increased too. With the IR-26, the cavity can be a LED or laser.

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Gupta, Shamindra Nath. "Die Effekte der Ca2+-Calmodulin-abhängigen Proteinkinase II (CaMKII) auf die Aktionspotential-morphologie bei mechanischer Last." Doctoral thesis, 2013. http://hdl.handle.net/11858/00-1735-0000-0001-BBFF-7.

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Tsai-LingChung and 鍾采凌. "The Solder Joint of Flip Chip Package due to Electromigration Effect by 3-D ANSYS with Electrothermal Coupling Method." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/36478608642517114061.

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碩士 國立成功大學 工程科學系 102 By focusing on a Flip-chip Packages, this study aims to discuss the failure behavior of the solder joint. An advanced electro-thermo coupling model is adopted. Furthermore, the input current value, the material compositions of the conductor layer and the thickness of the UBM are changed to analyze the location and its change of the voids. Therefore, the finite element analysis software ANSYS is applied to simulate and analyze the solder joints under electromigration. Subsequently, the current density distribution and the temperature distribution are investigated. Finally, the the input current value, the material compositions of the conductor layer and the thickness of the UBM are changed to investigate their effects on the current density, temperature and Joule heating in the model. The failure of a flip chip solder joint is always at cathode chip side where the voids appear initially based on the maximum value of current density and Joule heating. Accordingly, the void consistently expand along the interface of UBM and solder bump, and eventually leads to the failure of the solder joint. Then, the input current value, the material compositions of the conductor layer and the thickness of the UBM are changed to analyze the change of the current density distribution and the temperature distribution. It shows that all the current density, temperature and Joule heating increase at the current crowding spots when current input increases. Once the material composition of the conductor layer is changed to Cu, all the current density, temperature and Joule heating decrease at the current crowding spots. It also shows that current density and Joule heating at the current crowding spots with the thickness of the UBM is 0.45μm is larger than that with the thickness of 0.5μm or 0.55μm. For example, when current input is 40mA and the thickness of the UBM is 0.5μm , the current density at the current crowding spot on the UBM is 1.56x106A/cm2. Once the material compositions of the conductor layer is changed to Cu, the current density at the current crowding spots on the UBM is 1.27x106A/cm2. It is about 18.6% lower than before. However, when current input is 40mA and the material compositions of the conductor layer is still Al , the current density at the current crowding spot on the UBM becomes 61.5% increasing and is almost no change with the thickness of the UBM from the original 0.5μm to 0.45μm and 0.55μm respectively.

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Neumann, Kay. "Die Wirkung ionisierender Strahlung auf die elektromechanische Kopplung und den intrazellulären Ca2+-Haushalt in isolierten Herzmuskelzellen." Doctoral thesis, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-EFE7-A.

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Köhler, Anne Christine. "Die Bedeutung der Kalzium/Calmodulin-abhängigen Proteinkinase II für den gestörten Kalziumstoffwechsel der isolierten Rattenherzmuskelzelle unter Doxorubicinbehandlung." Doctoral thesis, 2013. http://hdl.handle.net/11858/00-1735-0000-0001-BAA9-2.

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50

Velikorodny, Alexey S. "Flow-induced sound and vibration due to the separated shear layer in backward-facing step and cavity configurations." Thesis, 2009. http://hdl.handle.net/1828/1898.

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Abstract:

Fully turbulent inflow past symmetrically located side branches mounted in a duct can give rise to pronounced flow oscillations due to coupling between separated shear layers and standing acoustic waves. Experimental investigation of acoustically-coupled flows was conducted using digital particle image velocimetry (DPIV) in conjunction with unsteady pressure measurements. Global instantaneous, phase- and time-averaged flow images, as well as turbulence statistics, were evaluated to provide insight into the flow physics during flow tone generation. Onset of the locked-on resonant states was characterized in terms of the acoustic pressure amplitude, frequency and the quality factor of the resonant pressure peak. Structure of the acoustic noise source is characterized in terms of patterns of generated acoustic power. In contrast to earlier work, the present study represents the first application of vortex sound theory in conjunction with global quantitative flow imaging and numerical simulation of the 2D acoustic field. In addition to the basic side branch configuration, the effects of bluff rectangular splitter plates located along the centerline of the main duct was investigated. The first mode of the shear layer oscillation was inhibited by the presence of plates, which resulted in substantial reduction of the amplitude of acoustic pulsations and the strength of the acoustic source. These results can lead to the development of improved control strategies for coaxial side branch resonators. Motivation for the second part of this study stems from the paper manufacturing industry, where air clamp devices utilize high-speed jets to position paper sheets with respect to other equipment. Thus, vibration of the paper sheet and turbulent flow that emerged from a planar curved nozzle between a flexible wall and a solid surface containing a backward-facing step (BFS) were investigated using high-speed photography and DPIV, respectively. The emphasis was on the characterization of the flow physics in the air clamp device, as well as of the shape of the paper sheet. For the control case, that involved a solid wall with a geometry that represented the time-averaged paper profile, hydrodynamic oscillation frequencies were characterized using unsteady pressure measurements. Experimentally obtained frequencies of the paper sheet vibration were compared to the hydrodynamic frequencies corresponding to the oscillations of the shear layer downstream of the BFS.

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