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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Implementing π-calculus style actions

Holton, David R.W. January 2008 (has links)
Yes / This technical report describes one technique for implementing π-calculus style actions in a programming language. It first attempts to clarify the nature of actions, then gives requirements a primitive in a programming language must satisfy if it is to be used as the basis for the implementation of actions. Finally an example is given of how actions may be implemented in Ada.
2

Syntéza a studium vlastností derivátů tetrathiofulvalenu / The tetrathiofulvalene derivatives: Their synthesis and properties

Nejedlý, Jindřich January 2012 (has links)
The goal of the diploma thesis was to prepare a spectrum of electron-rich macrocyclic derivatives of tetrathiafulvalene (TTF), which should serve as electron donors in interactions with electron-deficient acceptor molecules. A two-step synthesis was used for their preparation. First, a non-cyclic three-segment precursor was prepared by a reaction of a thiolate TTF construction block with a bis(bromomethyl)aromate. Then, a reaction of this precursor with another molecule of bis(bromomethyl)derivative closed the macrocycle. The latter reaction produced mainly [2+2] macrocycles containing two TTF and two aromatic units. In most cases, larger [4+4] macrocycles were also isolated from the reaction mixture. Besides thiolate TTF unit two other thiolate units, one with extended TTF core and other with smaller trithiafulvene ring, were used analogically in synthesis. By a combination of three thiolate blocks and five bis(bromomethyl)aromates 11 three-segment components were prepared and these were converted to 11 structural types of macrocycles with [2+2] and 7 macrocycles with [4+4] stoichiometry. The resulting macrocycles were characterized by 1 H a 13 C NMR spectroscopy and analyzed by a gel permeation chromatography. Their structures were also confirmed by high-resolution mass spectroscopy. Interaction...
3

A constante π

SILVA, Messias Antônio da 14 August 2015 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-29T14:11:57Z No. of bitstreams: 1 Messias Antonio da Silva.pdf: 2977132 bytes, checksum: a15679b5cedd2062e4385683b350d5f3 (MD5) / Made available in DSpace on 2017-03-29T14:11:57Z (GMT). No. of bitstreams: 1 Messias Antonio da Silva.pdf: 2977132 bytes, checksum: a15679b5cedd2062e4385683b350d5f3 (MD5) Previous issue date: 2015-08-14 / The constant π will be presented in this work since its origin, in length and area problems particularly the problem of squaring a circle -, to the most recent researches on algorithms used for the calculus of its decimal expansion. Using the exhaustion method we calculate the length and area of a circle of radius r. We demonstrate the irrationality of π . We also generalize the constant for π convex, simple and closed curves. At last we suggest some educational activities related to the concepts in study. / A constante π será apresentada desde a sua origem, nos problemas de medidas de comprimento, área, em particular o problema da quadratura do círculo, até as pesquisas mais recentes sobre os algoritmos usados para o cálculo, de sua expansão decimal. Usando o método da exaustão calculamos o comprimento e a área de um círculo de raio r. Mostramos a irracionalidade de π . Apresentamos uma generalização de π para curvas fechadas, simples e convexas. Finalmente, sugerimos algumas atividades didáticas envolvendo os conceitos estudados.
4

Architectures stimulables à base de foldamères photo- et électroactifs / Stimuli-responsive architectures based on photo- or electroactive foldamers

Faour, Lara 27 November 2018 (has links)
Les foldamères de type oligopyridine biscarboxamide constituent une famille d’oligomères synthétiques pouvant adopter une structure hélicoïdale et s’hybrider pour former des hélices doubles. Ce travail a eu pour objectif de synthétiser une nouvelle génération de foldamères π-fonctionnels porteurs de groupements photoactifs ou électroactifs, d’étudier les facteurs gouvernant l’équilibre entre hélice simple et hélice double, d’analyser l’impact de cet équilibre sur les propriétés optiques, et enfin de mettre en place un nouveau type de stimulus permettant de contrôler cet équilibre. Deux foldamères photoactifs dotés d’unités Disperse Red, ont été synthétisés. Leurs structures cristallographiques confirment la formation de structures hélicoïdales. Un choix précis du solvant permet d’orienter sélectivement l’équilibre vers la formation d’une hélice simple ou double.Le contrôle de l’équilibre d’hybridation par dilution permet de moduler l’activité en Génération de Seconde Harmonique du foldamère. En outre, la cavité générée par l'hélice permet la reconnaissance de divers anions. Enfin, les premiers efforts fournis pour induire une hélicité donnée à ces foldamères par voie supramoléculaire sont décrits. Par ailleurs, un foldamère électroactif fonctionnalisé par deux unités tétrathiafulvalène (TTF) a été synthétisé selon une méthodologie originale. La présence des unités TTF permet un contrôle redox inédit de la structuration du foldamère, par dimérisation de cations radicaux. Le concept a été élargi via l’immobilisation d’un foldamère sur surface d’or (SAMs). Enfin, une capsule électroactive capable de complexer l’acide tartrique a également été synthétisée et caractérisée. / Oligopyridine biscarboxamide-based foldamers constitute a family of synthetic oligomers that can fold into helical structures and hybridize to form double helices. This work aims at synthesizing a new generation of π-functionalized foldamers featuring photoactive and electroactive moieties, in order: to study the factors governing the equilibrium between simple and double helices, to analyze the impact of this equilibrium on the optical and recognition properties, and to set up a new type of stimulus to control this equilibrium. Two photoactive foldamers of different lengths and bearing two Disperse Red units were synthesized. Their crystallographic structures confirm the formation of helical structures. A precise choice of the solvent allows to drive the equilibrium towards the single or the double helix selectively.The cavity generated within the helix presents a good affinity for anions. The control over the hybridization equilibrium allows modulating the Second Harmonic Generation activity. Eventually, our first efforts to control the helicity of these foldamers through supramolecular chiral induction are described. On the other hand, an electroactive foldamer featuring two tetrathiafulvalene (TTF) units was synthesized according to an original methodology. The presence of TTF units allows an unprecedented redox control of the structure of foldamer, by dimerization of radical cations. The concept has been extended by immobilizing a foldamère on a gold surface (SAMs). Finally, an electroactive capsule capable of complexing tartaric acid has also been synthesized and characterized.
5

I. Exploration of Amphitropic Protein Interactions at the Membrane Interface; II. DNF2—A Plant Protein with Homology to Bacterial PI-PLC Enzymes

He, Tao January 2015 (has links)
Thesis advisor: Mary F. Roberts / Amphitropic proteins, such as the virulence factor phosphatidylinositol-specific phospholipase C (PI-PLC) from Bacillus thuringiensis, often depend on lipid-specific recognition of target membranes. However, the recognition mechanisms for zwitterionic lipids such as phosphatidylcholine (PC), which is enriched in the outer leaflet of eukaryotic cell membranes, are not well understood. Molecular dynamics (MD) simulation and mutagenesis results strongly indicate that PI-PLC interacts with PC head groups via cation-π interactions with aromatic tyrosine residues, and suggest that cation-π interactions at the interface may be a mechanism for specific lipid recognition by amphitropic and membrane proteins. Aromatic amino acids can not only form cation-π interactions at the interface but also insert into membranes and have hydrophobic interactions with lipid tails. Heretofore there has been no facile way to differentiate these two types of interactions. We show that specific incorporation of fluorinated amino acids into proteins can experimentally distinguish cation-π interactions from membrane insertion of the aromatic side-chains. Fluorinated aromatic amino acids destabilize the cation-π interactions by altering electrostatics of the aromatic ring while their enhanced hydrophobicity enhances membrane insertion. Incorporation of pentafluorophenylalanine or difluorotyrosine into a Staphylococcus aureus phosphatidylinositol-specific phospholipase C (PI-PLC) variant engineered to contain a specific PC-binding site demonstrates the effectiveness of this methodology. Applying this methodology to the plethora of tyrosine residues in Bacillus thuringiensis PI-PLC identifies those involved in cation-π interactions with PC. Cation-π interactions provide a likely molecular mechanism for BtPI-PLC PC specificity but do not account for its preference for bilayers containing a small fraction of anionic lipids. MD simulations and fluorescence correlation spectroscopy (FCS) vesicle binding measurements of positively charged amino acids as well as surface tyrosine residues are used to formulate a complete model of BtPI-PLC specific binding to mixed anionic phospholipid/PC membrane. DNF2, a new plant protein with homology to bacterial PI-PLC, is confirmed to be the first plant small PI-PLC enzyme that can cleave both PI and glycosylphosphatidylinositol (GPI) anchored proteins. GPI-anchored protein cleavage also confirms that DNF2 plays an important role in symbiosome, the intracellular compartment formed by the plant that contains nitrogen fixing bacteria. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
6

Numericamente igual a π / Numerically equal to π

Marques, Túlio Guimarães 01 March 2013 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-21T14:25:51Z No. of bitstreams: 2 Dissertação - Túlio Guimarães Marques - 2013.pdf: 3490137 bytes, checksum: a39789fad1b421e22443faee08545072 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-24T10:17:57Z (GMT) No. of bitstreams: 2 Dissertação - Túlio Guimarães Marques - 2013.pdf: 3490137 bytes, checksum: a39789fad1b421e22443faee08545072 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-24T10:17:57Z (GMT). No. of bitstreams: 2 Dissertação - Túlio Guimarães Marques - 2013.pdf: 3490137 bytes, checksum: a39789fad1b421e22443faee08545072 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-03-01 / Outras / This paper aims at introducing the science which is behind the most intriguing number known to history, the number . It has challenged generations of researchers who have tried to determine its value and articulate several areas of Mathematics such as Geometry, Algebra and Analysis. The quotient of ratio between the measure of the length of a circumference and the measure of its diameter are what de ne . Some historical references such as Archimedes, Euler, Leibniz and Lindemann have signi cantly contributed with the methods to precise . The rst real academic approach to this ratio was studied by the greatest mathematician of antiquity, Archimedes, when he created an instructive process for the study of the limits. With the unsolvable problem of the quadrature of the circle, ingenious geometrical constructions are born, in order to allow the drawing, with a ruler and compass, of a square having the same area as a previous given circle. The evolution of the forms employed in order to calculate have become more evident with the introduction of Analysis applied under the foundations of Calculus. At that time, the Series come to life, indispensable tools allowing the study of the behaviour of its decimal places. Along with the advances brought by them, the investigations turned towards the classi cation concerning the rationality or the irrationality of the number. In the end, we will present some contextualization and propose exercises with the aim of stimulating the search for knowledge. / O trabalho a seguir apresenta a ciência por trás do número mais intrigante da história, o número . Ele tem desa ado gerações de pesquisadores a determinar o seu valor e articular as várias áreas da matemática, como a Geometria, a Álgebra e a Análise. O quociente da razão entre a medida do comprimento de uma circunferência e a medida de seu diâmetro de ne . Algumas referências históricas, entre eles, Arquimedes, Euler, Leibniz e Lindemann, contribuíram signi cantemente nos métodos para precisar . A primeira abordagem realmente acadêmica dessa razão foi estudada pelo maior matemático da antiguidade, Arquimedes, quando ele criou um processo instrutivo no estudo dos limites. Com o insolúvel problema da quadratura do círculo, surgem construções geométricas engenhosas na tentativa de desenhar, com régua e compasso, um quadrado de mesma área de um círculo dado. A evolução das formas utilizadas para o cálculo do tornou-se mais evidente com a introdução da Análise aplicada nos fundamentos do Cálculo. Neste momento, surgem as Séries, ferramentas indispensáveis para estudar o comportamento de suas casas decimais. Com os avanços obtidos por estas, as investigações voltaram-se para classi cação quanto a racionalidade ou irracionalidade do número . Inicialmente a irracionalidade foi provada e mais tarde sua transcendência. Por m, são apresentadas algumas contextualizações e propostas de exercícios com a tentativa de estimular a busca por conhecimento.
7

Studies on Synthesis and Properties of Heteroarene-Containing π-Conjugated Compounds Having Spirofluorene Moieties / スピロフルオレン構造を有するπ共役複素環化合物の合成と物性に関する研究

Kowada, Toshiyuki 23 March 2010 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第15390号 / 工博第3269号 / 新制||工||1492(附属図書館) / 27868 / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 大江 浩一, 教授 辻 康之, 教授 村田 靖次郎 / 学位規則第4条第1項該当
8

Studium rozpadů τ-leptonů v experimentu Belle II / Study of the τ lepton decays at the Belle II experiment

Gruberová, Zuzana January 2021 (has links)
This master thesis describes the measurement of the π0 reconstruction efficiency correc- tion using τ-pair events from the Belle II experiment. The review part of the thesis begins with an overview of the Standard Model and the Belle II experiment, its detector system and the simulation software. This is followed by the description the τ-pair events and the method used for measuring the π0 reconstruction efficiency correction. The central part focuses on the event selection and the extraction of the signal yields. The results present the measured values of the average and momentum dependent π0 reconstruction efficiency correction, an improved π0 selection optimized for τ-lepton analyses, and a dedicated study on photon timing selection requirements. 1
9

Studies on Optoelectronic Properties of Structurally Confined Conjugated Molecules and Molecular Aggregates / 規定された共役構造を有する分子の凝集制御と光電子物性に関する研究

Hattori, Yusuke 26 September 2022 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第24236号 / 工博第5064号 / 新制||工||1790(附属図書館) / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 関 修平, 教授 今堀 博, 教授 杉安 和憲 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
10

O número π: Seus encantamentos e aplicações ao longo do tempo

Vieira, José Alexandre Ramos 24 March 2017 (has links)
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-07-17T12:46:42Z No. of bitstreams: 1 PDF - José Alexandre Ramos Vieira.pdf: 8487714 bytes, checksum: 7269a58a442aaf003f4fe818fa165ca6 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2017-07-18T20:54:28Z (GMT) No. of bitstreams: 1 PDF - José Alexandre Ramos Vieira.pdf: 8487714 bytes, checksum: 7269a58a442aaf003f4fe818fa165ca6 (MD5) / Made available in DSpace on 2017-07-18T20:54:28Z (GMT). No. of bitstreams: 1 PDF - José Alexandre Ramos Vieira.pdf: 8487714 bytes, checksum: 7269a58a442aaf003f4fe818fa165ca6 (MD5) Previous issue date: 2017-03-24 / The presentworkshows a brief history regarding thenumber π. Let’s look atsome ideas developed from the quest to understand and calculate this important number that has fascinated mathematicians since antiquity. We begin by approaching the irra- tionality of π, and then recall the classic Greek problem of Circle Quadrature and how this problem was needed to calculate this constant as accurately as possible. We will also comment on the historical attempts to calculate it, with emphasis on the methods developed by Archimedes, Nicholas of Cusa, Leibniz, Machin and Wallis, through which we can calculate thenumber π very quickly and accurately. Finally, we will do a comparative analysis of the methods seen, displaying some charts and approximation tables calculated with the support of the Geogebra Educational Software. / O presente trabalho mostra um breve histórico a respeito do número π. Vamos ver algumas ideias desenvolvidas a partir da busca de compreender e calcular este importante número que tem fascinado os matemáticos desde a antiguidade. Começaremos abordando a irracionalidade de π e, em seguida, recordaremos o clássico problema grego da Quadratura do Círculo e como este problema contribuiu para o cálculo dessa constante da maneira mais exata possível. Comentaremos,também, sobre as tentativas históricas de calculá-lo, dando ênfase aos métodos desenvolvidos por Arquimedes, Nicholas de Cusa, Leibniz,Machin eWallis, através dos quais podemos calcular o número π com muita rapidez e exatidão. Finalmente, faremos uma análise comparativa dos métodos vistos, exibindo alguns gráficos e tabelas de aproximações calculadas com o apoio do Software Educacional Geogebra.

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