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Josephson transistors interacting with dissipative environmentLeppäkangas, J. (Juha) 14 April 2009 (has links)
Abstract
The quantum-mechanical effects typical for single atoms or molecules can be reproduced in micrometer-scale electric devices. In these systems the essential component is a small Josephson junction (JJ) consisting of two superconductors separated by a thin insulator. The quantum phenomena can be controlled in real time by external signals and have a great potential for novel applications. However, their fragility on uncontrolled disturbance caused by typical nearby environments is a drawback for quantum information science, but a virtue for detector technology.
Motivated by this we have theoretically studied transistor kind of devices based on single-charge tunneling through small JJs. A common factor of the research is the analysis of the interplay between the coherent Cooper-pair (charge carriers in the superconducting state) tunneling and incoherent environmental processes. In the first work we calculate the current due to incoherent Cooper-pair tunneling through a voltage-biased small JJ in series with large JJs and compare the results with recent experiments. We are able to reproduce the main experimental features and interpret these as traces of energy levels and energy bands of the mesoscopic device. In the second work we analyze a similar circuit (asymmetric single-Cooper-pair transistor) but under the assumption that the Cooper-pair tunneling is mainly coherent. This predicts new resonant transport voltages in the circuit due to higher-order processes. However, no clear traces of most of them are seen in the experiments, and similar discrepancy is present also in the case of the symmetric circuit. We continue to study this problem by modeling the interplay between the coherent and incoherent processes more accurately using a density-matrix approach. By this we are able to demonstrate that in typical conditions most of these resonances are indeed washed out by strong decoherence caused by the environment. We also analyze the contribution of three typical weakly interacting dissipative environments: electromagnetic environment, spurious charge fluctuators in the nearby insulating materials, and quasiparticles. In the last work we model the dynamics of a current-biased JJ perturbed by a smaller JJ using a similar density-matrix approach. We demonstrate that the small JJ can be used also as a detector of the energy-band dynamics in a current biased JJ. The method is also used for modeling the charge transport in the Bloch-oscillating transistor.
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Vybrané strategie burzovních obchodů / Stock market strategiesNováček, Jakub January 2011 (has links)
This thesis presents two different types of stock trading for a small investor. First described method focuses on stocks from abroad, where with the help of technical analysis a portfolio is constructed. This portfolio is to be traded with the strategy of pair trading or sometimes also called statistical arbitrage. This method is not very well known, so the thesis gives enough space to explain how the system exactly works. Second strategy puts focus on stocks from Prague Stock Exchange and their trading as dividend stocks. Unlike the first strategy, this one presents the fundamental analysis and longterm investment. The emphasis is in both strategies put on easily managable portfolio and its good revenue.
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Tone variation in Tswana-speaking individuals : the effect of voice disordersJones, Gail L. January 2016 (has links)
Introduction: Bantu languages, such as Tswana, are tone languages which use syllabic tone variation to convey word meaning. Vocal pathologies may affect vocal fold control that is required to vary syllabic tone. A person with a voice disorder could therefore be misperceived due to inability to effectively vary tone. Aim: To develop and validate a Tswana minimal pair word list for the assessment of tone production and tone perception, and to determine whether a voice disorder in a first language (L1) Tswana-speaker influences the accuracy of tone perception by typical L1 Tswana-speaking individuals. Method: A word list of 45 Tswana words, with accompanying pictures and sentences were compiled and validated by means of three pilot studies. Based on the results of the pilot studies the word list was narrowed down to 16 minimal pairs. Data were collected from a control group (9 typical L1 Tswana-speaking individuals) and an experimental group (5 L1 Tswana-speaking individuals with voice disorders). Participants from both groups produced the target words and a recording of each word production was judged by a listeners’ panel of five typical L1 Tswana-speaking judges. Results: Typical L1 Tswana listeners did not achieve 100% accuracy in a tone perception task. The mean scores of the control speakers ranged between 71% and 98%. The experimental group participants’ scores were lower although not significantly lower (p=0.109), ranging between 61% and 90%, compared to the scores of the control group. The experimental participant, who obtained the lowest mean score (61%), presented with a severe primary organic voice disorder. Conclusion: Not all typical speakers were able to produce word-level tone variation that makes word identification possible in a single-word context. Although no significant difference was found between the results of the two groups, indications are that a voice disorder could negatively impact syllabic tone variation. / Dissertation (MCommunication Pathology)--University of Pretoria, 2016. / Speech-Language Pathology and Audiology / MCommunication Pathology / Unrestricted
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The Secret Art of Science: An Aural-Based Analysis of Jonty Harrison's Acousmatic Work "Pair/Impair"Vega, Henry 08 1900 (has links)
This paper observes the problems that impede meaningful analysis of form and structure in modern music, specifically electronic music. The premise of this research is to present methods, tools and practice for analyzing music whose visual interpretation, if any, do not represent the aural result of the composition. The means for suggesting a method are derived from documented observations in aural psychology, as well as composers' writings about musical perception. The result is an analytic model that focuses on the aural experience rather than the composers' compositional strategies which do not always agree with the resultant composition. The results from the analysis of music by Parmegiani, Harvey, Vega and Harrison help prove the general applicability of this research.
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Genetic and behavioral correlates of pair living in coppery titi monkeys (Plecturocebus cupreus)Dolotovskaya, Sofya 07 October 2020 (has links)
No description available.
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Enantioselective Transformations Promoted by Cooperative Functions of an Achiral Lewis Acid and a Chiral Lewis Acid:Cao, Min January 2021 (has links)
Thesis advisor: Masayuki Wasa / Thesis advisor: Amir H. Hoveyda / This dissertation describes the development of cooperative catalyst systems that contain an achiral Lewis acid and a chiral Lewis acid that may have overlapping functions but play their independent roles to promote enantioselective C–C bond formations. Chapter 1 provides a summary of recent advances made in the field of enantioselective cooperative catalysis that served as intellectual foundations for this dissertation research. As it will be discussed in the first chapter, key limitations of cooperative catalysis are: (1) undesirable catalyst deactivation which occurs due to acid/base complexation, (2) requirement for base sensitive pronucleophiles and acid sensitive electrophiles, and (3) poor reaction efficiency. In an effort to overcome these fundamental limitations, we have developed “frustrated” Lewis pair (FLP)-based catalyst systems that consist of potent and sterically encumbered Lewis acids used in pair with bulky N-containing Lewis bases. To demonstrate the potential of the novel FLP catalyst system, we describe our work involving the enantioselective Conia-ene-type cyclization (Chapter 2). In the subsequent chapter (Chapter 3), we discuss the application of the FLP catalysts for enantioselective β-amino C–H functionalization reactions. / Thesis (PhD) — Boston College, 2021. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
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A Biocomputational Study of Water-Nucleobase Stacking Contacts in Functional RNAsKalra, Kanav 12 1900 (has links)
Recent structural studies evidenced the presence of a recurring well-known interaction between an oxygen atom and an aromatic nucleobase ring in structural motifs of nucleic acids. In particular, this type of interaction is observed between the O4' atom of the (deoxy)ribose moiety and the aromatic nucleobase in Z-DNA molecules and in a variety of structural RNA molecules. In this thesis, we comprehensively examine the hitherto undetected stacking interactions between an oxygen atom of a water (Ow) molecule and the aromatic nucleobase ring, using structural bioinformatics along with quantum mechanics. On the basis of the structural analysis of the high-resolution X-ray structures, we found out that the stacking distance between the Ow atom and the nucleobase plane varies between 3.1 and 4.0 Å. Further, the contact between the Ow-nucleobase plane can be categorized either as a lonepair-π type, where the Ow atom interacts directly with the aromatic surface of the nucleobase, or as an OH-π interaction, where one of the hydrogen atoms of the Ow points towards the nucleobase. Our quantum chemical analysis evidenced that the OH-π interaction is clearly favored in terms of energetics when compared to the lonepair-π, except for the uracil, where the lonepair-π kind of interaction seems to be energetically more stable, as also supported by electrostatic potential map calculations.
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ADS/CFT correspondence in a non-supersymmetric Yi-deformed backgroundPrinsloo, Andrea Helen 22 December 2008 (has links)
A non-supersymmetric
Yi-deformed AdS/CFT correspondence has recently been conjectured
by Frolov. A detailed description of both sides of this proposed gauge/string
duality is presented. The analogy that exists between single trace gauge theory operators
in the SU(3) sector and
i-deformed SU(3) integrable spin chains is also
discussed. Frolov, Roiban and Tseytlin’s leading order comparison between the
ideformed
spin chain coherent state action and
i-deformed string worldsheet action
in the semiclassical limit is reviewed. A particular Lax pair representation for the
first order semiclassical
i-deformed spin chain/string action is then constructed.
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Aspects of the Ecology and Management of Mottled Ducks in Coastal South CarolinaShipes, James Claybourne 13 December 2014 (has links)
Mottled ducks (Anas fulvigula) are endemic to Gulf Coastal United States and Mexico. Birds from Florida, Louisiana, and Texas were released in coastal South Carolina from 1975-1983, and banding data suggest an expanding South Carolina population. We radio-marked 116 females in August 2010-2011 in the Ashepoo, Combahee, and Edisto (ACE) Rivers Basin and used radio telemetry to study habitat selection, searched for nests of non-radiomarked females, and conducted indicated breeding pair surveys of mottled ducks at various wetlands. Overall, radiomarked mottled duck females selected managed wetland impoundments, wetlands containing planted corn, and brackish wetlands. Overall nest success of 42 nests of unmarked females was 19%. Modeling results indicated that the area of an island on which a nest was located was the only variable influencing nest success. Indicated breeding pair surveys revealed that the size of the wetland was the primary influence of breeding mottled duck immigration into a wetland.
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Calculating Ion Pair Production within the Icet Hepa Filter Test Stand Aerosol Neutralizer and Radiation Dose Rates from Mobile Surveying System DataUnz, Ronald James 12 May 2012 (has links)
Aerosols generated in the Institute for Clean Energy (ICET) High-Efficiency Particulate Air (HEPA) filter test stand become charged due to triboelectric processes during production. High-activity beta sources are used to generate ion pairs within the HEPA test stand. The generated ion pairs bind with aerosols to effectively neutralize surface charges on the aerosols. Several methods to calculate the ion pair concentration within the HEPA test stand are described. Several buildings at Oak Ridge National Lab (ORNL) have been slated for decontamination and decommissioning. Contaminating isotopes must be identified and located. Systematic surveys using gamma-ray scintillation detectors can be used to locate and identify gamma-emitting isotopes. Discussed are methods that use gamma-ray spectroscopy data collected during surveys to locate, identify, determine source strength and corresponding dose rates. Survey data are then used to construct radiation intensity and dose rate maps of the interior of the surveyed structures.
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