Log in

Relevant bibliographies by topics / COLD TRAPS / Dissertations / Theses

To see the other types of publications on this topic, follow the link: COLD TRAPS.

Dissertations / Theses on the topic 'COLD TRAPS'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'COLD TRAPS.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Cooper, Catherine J. "Laser cooling and trapping of atoms." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308685.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Burrows, Kathryn Alice. "Non-adiabatic losses from radio frequency dressed cold atom traps." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/61380/.

Full text

Abstract:

Cold atom traps are a promising tool for investigating and manipulating atomic behaviour. Radio frequency (RF) dressed cold atom traps allow high versatility of trapping potentials, which is important for potential applications, particularly in atom interferometry. This thesis investigates non-adiabatic spin flip transitions which can lead to losses of atoms from RF-dressed cold atom traps. We develop two models for the adiabatic potentials associated with RF-dressed traps, for the cases in which gravity does and doesn't have a significant effect. Within these two models we use first order per

APA, Harvard, Vancouver, ISO, and other styles

3

Morsch, Oliver. "Optical lattices for ultra-cold atoms." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301174.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Ivanov, Vladyslav Victorovych. "Cold atoms modified radiative properties and evaporative cooling from optical traps /." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2007. http://dare.uva.nl/document/47332.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Deb, Amita. "Theoretical and experimental studies on ultra-cold atoms in optical traps." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.600174.

Full text

Abstract:

This thesis describes a number of theoretical and experimental studies on the production, manipulation and detection of ultra-cold atoms in arrays of optical traps, i. e. optical lattices for applications such as direct quantum simulation of many-body systems and quantum information processing. A method of deterministically preparing a single atom in each site of an optical lattice is explored and the parameter regime that would be required to implement this protocol in experiments is investigated. A novel method of state-selective spatial transfer of atoms between neighbouring sites of a latt

APA, Harvard, Vancouver, ISO, and other styles

6

Sand, Karl Jakob. "On the Design and Simulation of Electromagnetic Traps and Guides for Ultra-Cold Matter." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11733.

Full text

Abstract:

The objective of this thesis is the design and simulation of new electromagnetic traps and guides for ultra-cold matter. The traps and guides are intended for future experiments with small amounts of alkali atoms to study the quantum-mechanical effects of condensation and coupling between trapped drops of cold matter. The main results are with the development and simulation of new wire traps and guides based on the dressing effect realised in strong DC magnetic and RF fields of certain frequencies. Some designs are proposed using only trapping by the DC magnetic field. The principal methodolog

APA, Harvard, Vancouver, ISO, and other styles

7

De, Palatis Michael V. "Production of cold barium monohalide ions." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50251.

Full text

Abstract:

Ion traps are an incredibly versatile tool which have many applications throughout the physical sciences, including such diverse topics as mass spectrometry, precision frequency metrology, tests of fundamental physics, and quantum computing. In this thesis, experiments are presented which involve trapping and measuring properties of Th³⁺. Th³⁺ ions are of unique interest in part because they are a promising platform for studying an unusually low-lying nuclear transition in the 229Th nucleus which could eventually be used as an exceptional optical clock. Here, experiments to measure electronic

APA, Harvard, Vancouver, ISO, and other styles

8

Sanguinetti, Stefano. "ATOMIC PARITY VIOLATION IN HEAVY ALKALIS: Detection by Stimulated Emission for Cesium and Traps for Cold Francium." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00006785.

Full text

Abstract:

Le travail présenté porte sur les progrès récents d'expériences de spectroscopie atomique sur césium et francium, visant à des mesures précises de violation de parité (PV) dans ces atomes. Dans le cadre d'une “thèse en cotutelle”, le candidat s'est consacré d'une part aux mesures PV préliminaires (8% de précision) de l'actuelle expérience Cs au LKB à Paris, et d'autre part à la préparation d'un échantillon d'atomes radioactifs de Fr (production et piégeage) aux LNL (INFN) en Italie. Ces deux expériences sont à des stades très différents. Les mesures présentées pour le Cs s'inscrivent en fait d

APA, Harvard, Vancouver, ISO, and other styles

9

Kim, Soo Y. "Cold single atoms for cavity QED experiments." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26581.

Full text

Abstract:

Thesis (Ph.D)--Physics, Georgia Institute of Technology, 2009.<br>Committee Chair: Chapman, Michael; Committee Member: Citrin, David; Committee Member: Kennedy, T. A. Brian; Committee Member: Kuzmich, Alexander; Committee Member: Raman, Chandra. Part of the SMARTech Electronic Thesis and Dissertation Collection.

APA, Harvard, Vancouver, ISO, and other styles

10

Halkyard, Paul Lee. "Dynamics in cold atomic gases : resonant behaviour of the quantum delta-kicked accelerator and Bose-Einstein condensates in ring traps." Thesis, Durham University, 2010. http://etheses.dur.ac.uk/529/.

Full text

Abstract:

In this thesis, the dynamics of cold, trapped atomic gases are investigated, and the prospects for exploiting their nonlinear dynamics for inertial sensing are discussed. In the first part, the resonant and antiresonant dynamics of the atom-optical quantum delta-kicked accelerator with an initial symmetric momentum distribution are considered. The system is modelled as an ideal, non-interacting atomic gas, with a temperature-dependence governed by the width of the initial momentum distribution. The existence of resonant and antiresonant behaviour is established, and analytic expressions descri

APA, Harvard, Vancouver, ISO, and other styles

11

Bruce, Graham D. "Alternative techniques for the production and manipulation of ultracold atoms." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/2617.

Full text

Abstract:

This Thesis contains details of the construction and characterisation of a compact apparatus for the cooling of ultracold atoms to quantum degeneracy, and their manipulation in flexible holographic optical traps. We have designed and built two iterations of this apparatus. The first version consists of a stainless steel single-cell vacuum chamber, in which we confine ⁸⁷Rb and ⁶Li or ⁷Li in a Magneto-Optical Trap. We characterise the alternative methods of pulsed atomic dispenser and Light Induced Atomic Desorption (LIAD) to rapidly vary the background pressure in the vacuum chamber with the vi

APA, Harvard, Vancouver, ISO, and other styles

12

Webster, Stephen. "Prospects for Bose-Einstein condensation in caesium : cold collisions and dipole-force trapping." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325563.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Clements, Ethan Robert. "CHARACTERIZATION OF OPTICAL LATTICES USING PUMP-PROBESPECTROSCOPY AND FLUORESCENCE IMAGING." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1470323164.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Walker, Graeme. "Trans-spectral transfer of orbital angular momentum and creation of an ultra high density cold atom trap." Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/4498/.

Full text

Abstract:

In recent years there has been great interest in the applications of the interaction of the phase and intensity of laser light in atomic vapours. The generation of light beams with arbitrary phase and intensity patterns can now be easily achieved by using Spatial Light Modulators (SLMs). The transformation of quantized units of phase information to atomic vapours has implications in the ﬁelds of quantum optics for the realisation of sources of entangled photons, optical switching, and quantum information storage. Spatially shaped beams with non-trivial intensity geometries have found use in si

APA, Harvard, Vancouver, ISO, and other styles

15

Simoneau-Roy, Maxime. "Le riborégulateur thiB d'Escherichia coli : une régulation en trans?" Mémoire, Université de Sherbrooke, 2014. http://hdl.handle.net/11143/5377.

Full text

Abstract:

La régulation de l’expression génétique est essentielle afin qu’un organisme puisse s’adapter aux changements environnementaux. Chez les bactéries, la régulation peut s’effectuer à plusieurs étapes de l’expression des gènes (transcription, stabilité de l’ARN, traduction, maturation et dégradation des protéines) et par des mécanismes impliquant différents types de molécules (ADN, ARN, protéines, métabolites ou ions inorganiques). Traditionnellement, les protéines se situaient au centre de ces mécanismes de régulation. On sait maintenant que certains ARN, dont les riborégulateurs, ont également

APA, Harvard, Vancouver, ISO, and other styles

16

Dinkelaker, Aline. "Smooth inductively coupled ring trap for cold atom optics." Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=19200.

Full text

Abstract:

The main topic in this thesis is the proof-of-principle experiment for an inductively coupled magnetic ring trap for applications in atom interferometry and quantum gas investigations. Atom interferometry utilises the wave nature of atoms for precision measurements of gravitational and inertial effects and to test fundamental physics. Due to their symmetry, their periodic boundary conditions and their large enclosed areas, ring traps provide attractive geometries for atom interferometry. By tightening the trap and reducing the trap radius, toroidal traps also have excellent conditions to study

APA, Harvard, Vancouver, ISO, and other styles

17

Muckley, Eric S. "Constructing a magneto-optical trap for cold atom trapping /." Click here to view, 2009. http://digitalcommons.calpoly.edu/physsp/2.

Full text

Abstract:

Thesis (B.S.)--California Polytechnic State University, 2009.<br>Project advisor: Katharina Gillen. Title from PDF title page; viewed on Jan. 14, 2010. Includes bibliographical references. Also available on microfiche.

APA, Harvard, Vancouver, ISO, and other styles

18

Van, Dongen Janelle. "Simultaneous cooling and trapping of 6Li and 85/87Rb." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/351.

Full text

Abstract:

This thesis provides a summary of the laser system constructed in the Quantum Degenerate Gases Laboratory for laser cooling and trapping of 85/87Rband 6Li as well as of experiments that have been pursued in our lab to date. The first chapter provides an overview of the experimental focus of the QDG lab. The second and third chapters provide the fundamental theory behind laser cooling and trapping. The fourth chapter provides details of the laser system. The fifth chapter describes an experiment performed on the subject of dual-injection, performed in collaboration with Dr. James Booth of the B

APA, Harvard, Vancouver, ISO, and other styles

19

Pollum, Laura L. "Digital ion trap mass spectrometry for cold ion-molecule chemistry." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:18c6451d-d247-4384-9257-f8864e038343.

Full text

Abstract:

A promising new approach for studying cold ion-molecule chemical reactions is the combination of laser- or sympathetically-cooled trapped ions and slow-moving molecules from a cold molecule source, such as a quadrupole velocity selector or a Stark decelerator. Previous reaction studies using trapped atomic ions and slow molecules from a quadrupole velocity selector were able to reach average collision energies as low as 1 K. However, the guided molecules had an approximately room temperature rotational energy distribution, so the reactions studied were not truly cold. Thus, a new molecular sou

APA, Harvard, Vancouver, ISO, and other styles

20

Steer, Edward. "Development and characterisation of a cold molecule source and ion trap for studying cold ion-molecule chemistry." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:13c3a622-ba78-4a53-902c-666ec461f708.

Full text

Abstract:

A novel apparatus, combining buffer-gas cooling, electrostatic velocity selection and ion trapping, has been constructed and characterised. This apparatus is designed to investigate cold ion-molecule chemistry in the laboratory, at a variable translational and internal (rotational) temperature. This improves on previous experiments with translationally cold but rotationally hot molecule sources. The ability to vary the rotational temperature of cold molecules will allow for the experimental investigation of post-Langevin capture theories.

APA, Harvard, Vancouver, ISO, and other styles

21

Sarshar, Zahra. "Hydrocarbon trap adsorbents for reducing cold-start emissions of automotive exhaust." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25807/25807.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Shields, Brendan John. "Loading a planar RF Paul Trap from a cold Yb⁺ source." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36117.

Full text

Abstract:

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2006.<br>Includes bibliographical references (p. 61-63).<br>In this thesis, we demonstrate a functioning planar radio frequency, three-rod Paul Trap, loaded with Yb+ ions that have been photoionized from a source of neutral atoms, which were cooled in a magneto-optical trap. Planar ion traps have only recently been successfully loaded[1], and never from a cold ion source. Additionally, ionizing directly from a MOT allows for isotope selection.<br>by Brendan John Shields.<br>S.B.

APA, Harvard, Vancouver, ISO, and other styles

23

Thomas, Angharad Mair. "Ultra-cold collisions and evaporative cooling of caesium in a magnetic trap." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403426.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Sheridan, Kevin Thomas. "Experimental techniques for cold chemistry and molecular spectroscopy in an ion trap." Thesis, University of Sussex, 2013. http://sro.sussex.ac.uk/id/eprint/47145/.

Full text

Abstract:

A range of experimental techniques for application in reaction studies between ionic and neutral atoms/molecules and high resolution spectroscopy experiments with sympathetically cooled molecular ions are presented. A novel ion trap loading scheme using the photo-ionisation of atoms generated by the pulsed laser ablation of a solid calcium target has been characterised. We have identified the range of ablation laser fluences that must be used in order to produce a flux of neutral calcium atoms, which is a prerequisite for isotope selective ion trap loading. Calcium ions are trapped and laser c

APA, Harvard, Vancouver, ISO, and other styles

25

Ladouceur, Keith. "Experimental advances toward a compact dual-species laser cooling apparatus." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2508.

Full text

Abstract:

This thesis describes the advances made towards a dual-species magneto-optical trap (MOT) of Li and Rb for use in photoassociation spectroscopy, Feshbach resonance studies, and, as long-term aspirations, the formation of ultracold heteronuclear polar molecules. The initial discussion will focus on a brief theoretical overview of laser cooling and trapping and the production of ultracold molecules from a cold atom source. Subsequently, details of the experimental system, including those pertaining to the required laser light, the vacuum chamber, and the computer control system will be presented

APA, Harvard, Vancouver, ISO, and other styles

26

Pynn, Ralph M. "The Newfoundland and Labrador cod trap fishery : the basis for a future cod grow out industry /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ42432.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Braga, Helena Carolina. "O operador de Wigner aplicado a colisões de mudança de estrutura fina entre átomos alcalinos no regime frio." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-09042008-091650/.

Full text

Abstract:

Neste trabalho abordamos os processos de perdas colisionais por mudança de estrutura fina e por escape radiativo. Estes processos são importantes por serem os principais fatores limitantes da densidade e da permanência de átomos confinados em armadilhas magneto-ópticas. A utilização do formalismo de Wigner nos possibilitou tratar a dinâmica dos graus de liberdade internos do sistema de forma puramente quântica, enquanto tratamos os graus de liberdade translacionais de maneira semiclássica. Com este formalismo deduzimos equações inéditas para uma colisão unidimensional e desenvolvemos um algori

APA, Harvard, Vancouver, ISO, and other styles

28

Stoller, Gerlind. "Charakterisierung des Triggerfaktors - einer ribosomenassoziierten Peptidyl-Prolyl-cis-trans-Isomerase aus Escherichia coli." [S.l. : s.n.], 1998. http://deposit.ddb.de/cgi-bin/dokserv?idn=960869263.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Hu, Zhen Kimble H. Jeff Kimble H. Jeff. "Quantum optics with cold atoms--nonlinear spectroscopy and road toward single-atom trap /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-10112007-092812.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Binet, Emmanuelle. "Contrôle qualité des protéines er régulation par protéolyse et trans-traduction." Paris 11, 2001. http://www.theses.fr/2001PA112297.

Full text

Abstract:

Dans tout le règne du vivant, la protéolyse intervient non seulement dans l'élimination des protéines défectueuses, mais aussi dans la régulation de nombreux processus essentiels à la cellule. Différentes stratégies existent pour permettre aux protéases de reconnaître spécifiquement leurs cibles. L'une d'entre elles est de marquer les polypeptides à éliminer avec des signaux spécifiques reconnus par les protéases. Chez les procaryotes, il existe un système, dit SsrA, qui permet de cibler des polypeptides issus d'une traduction défectueuse vers la protéolyse. Par un mécanisme d'action particuli

APA, Harvard, Vancouver, ISO, and other styles

31

Prakash, Satya. "De novo engineering of trans-activating riboswitches in E. coli." Thesis, University of Warwick, 2018. http://wrap.warwick.ac.uk/114021/.

Full text

Abstract:

RNA molecules play a major role in cellular processes such as replication, transcription, and translation. As a result, RNA-based engineering methods have emerged as important tools in biotechnology. However, the structure and function of RNA depends on global interactions, which often prevents the use of a modular design strategy, particularly with allosteric conformations. Using RNA secondary structure prediction tools, computational methods can successfully design RNA switches that work in E. coli. The overarching aim of my research is to develop synthetic RNA switches that could be used fo

APA, Harvard, Vancouver, ISO, and other styles

32

Deb, Nabanita. "Towards cold state-selected ion-molecule reactions." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:1a3899d3-7476-49ac-8f4b-3c0e7a7e8680.

Full text

Abstract:

In recent years there has been much progress in the field of cold and ultracold molecular physics and a variety of experimental techniques for producing cold matter now exist. In particular, the generation of trapped molecular ions at mK temperatures has been achieved by sympathetic-cooling with laser-cooled atomic ions. By implementing schemes to selectively prepare and control the internal quantum state of molecular ions, and developing detection techniques, it will be increasingly possible to study cold state-selected chemical collisions in an ion-trap. Most molecular species produced in a

APA, Harvard, Vancouver, ISO, and other styles

33

Passagem, Henry Fernandes. "Fotoassociação de curto alcance em átomos de rubídio." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-11032016-111138/.

Full text

Abstract:

Neste trabalho, estudamos a fotoassociação de átomos de rubídio no regime de curto alcance. Realizamos espectroscopia por perda de átomos em uma armadilha magneto-óptica de 85Rb usando um laser de fibra de alta potência, o qual possuia largura de linha da ordem de 1MHz e 50W de potência no intervalo de 1060nm a 1070nm. Dois níveis vibracionais do potencial excitado 0u+ foram observados (v=137 e v=138). Além disso, medimos o tempo de vida de uma armadilha óptica de dipolo cruzada. Como esperado, o tempo de vida é menor quando o laser está sintonizado na ressonância. Um modelo teórico prevê a di

APA, Harvard, Vancouver, ISO, and other styles

34

Menegatti, Carlos Renato. "Armadilha de dipolo para átomos e moléculas." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-29082011-104357/.

Full text

Abstract:

Neste trabalho apresentamos a construção de um novo sistema experimental para aprisionamento de átomos e moléculas. Trata-se de uma armadilha de dipolo cruzada totalmente óptica, formada por um laser de fibra com 40 W de potência com comprimento de onda em 1064 nm. Nesse sistema foi demonstrado o aprisionamento de átomos Rb e K e moléculas Rb2. Realizamos dois experimentos distintos neste se novo sistema: No primeiro, estudamos a evolução temporal de amostras dos isótopos 85Rb e 87Rb na armadilha de dipolo cruzada. Pudemos medir pela primeira vez o processo de mudança de estrutura hiperfina em

APA, Harvard, Vancouver, ISO, and other styles

35

Marangoni, Bruno Spolon. "Colisões heteronucleares em uma armadilha de dipolo." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-24042013-111126/.

Full text

Abstract:

Neste trabalho, apresentamos uma montagem experimental capaz de aprisionar átomos de K e Rb simultaneamente em uma armadilha óptica de dipolo cruzada. Contudo, para atingir este feito foi necessário, durante o desenvolvimento do projeto, estudar cada espécie atômica de forma isolada. Assim, desenvolvemos uma técnica inédita para carregar uma armadilha de dipolo diretamente de uma armadilha magneto-óptica de 39K, constatando a importância da estrutura hiperfina do estado 4P3/2 no processo de carregamento. Também observamos e explicamos o processo de fotoassociação de Rb devido ao laser em 1071

APA, Harvard, Vancouver, ISO, and other styles

36

Kas, Milaim. "Cold chemistry of molecular anions: a theoretical investigation in the context of hybrid trap experiments." Doctoral thesis, Universite Libre de Bruxelles, 2018. https://dipot.ulb.ac.be/dspace/bitstream/2013/279061/4/main.pdf.

Full text

Abstract:

Hybrid trap experiments are set-ups that allow to study the interaction between ions and atoms in cold controlled environment. In such context, molecular anions present specific theoretical and experimental interests and challenges. In this work, we have used extensive \textit{ab initio} methods to investigate several collisional anionic systems: (1) M + OH$^{-}$ (where M are alkali or alkaline earth atoms), (2) Rb and H + OH(H$_{2}$O)$_{n}^{-}$ (with $n=0,1,2,3,4$) and (3) Rb and Li + C$_{2}^{-}$. Several molecular properties such as vertical detachment energies or electroaffinities, optimize

APA, Harvard, Vancouver, ISO, and other styles

37

Souther, Nathan Jon. "Light Shift Measurements of Cold Rubidium Atoms using Raman Pump-Probe Spectroscopy." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1250622906.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Borodi, Gheorghe. "On the combination of a low energy hydrogen atom beam with a cold multipole ion trap." Doctoral thesis, Universitätsbibliothek Chemnitz, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200900932.

Full text

Abstract:

Der erste Teil der Aktivitäten dieser Arbeit bestand in der Entwicklung einer modernen Ionenspeicher Apparatur zur Untersuchung chemischer Prozesse mit atomarem Wasserstoff. Die Integration eines differentiell gepumpten Radikalenstrahls in eine vorhandene temperaturvariable 22-Pol Speicherapparatur erforderte größere Änderungen an dieser. Da astrophysikalische Fragestellungen im Vordergrund standen, führt die Einleitung zunächst in das Gebiet der Astrophysik und -chemie ein. Die Grundlagen der Ionenspeicherung in temperaturvariablen Hf-Speichern sind ausführlich in der Literatur dokumentiert.

APA, Harvard, Vancouver, ISO, and other styles

39

Collier, Justine. "Déblocage de ribosomes et étiquetages de polypeptides par trans-traduction chez Escherichia coli." Paris 11, 2004. http://www.theses.fr/2004PA112047.

Full text

Abstract:

L’ARNtm et SmpB permettent la libération des ribosomes lorsque la traduction est défectueuse. Les polypeptides dont la biosynthèse est bloquée sont en même temps étiquetés, ce qui induit leur élimination par des protéases. Ce mécanisme est nommé trans-traduction. SmpB et l’ARNtm sont ubiquitaires chez les eubactéries. Nous montrons que les SmpB de plusieurs espèces bactériennes peuvent étiqueter des polypeptides avec l’ARNtm d’E. Coli in vivo, ce qui illustre la conservation fonctionnelle du système de trans-traduction. Nous montrons aussi que la trans-traduction n’est pas affectée in vivo à d

APA, Harvard, Vancouver, ISO, and other styles

40

Truppe, Stefan. "New physics with cold molecules : precise microwave spectroscopy of CH and the development of a microwave trap." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/18997.

Full text

Abstract:

Cold polar molecules provide unique opportunities to test fundamental physics and chemistry. Their permanent electric dipole moments and rich internal structure arising from their vibrational and rotational motion, makes them sensitive probes for new physics. These features also make them ideal for studying ultracold chemistry, for simulating the behaviour of strongly interacting many-body quantum systems, and for quantum information science. This thesis describes a number of advances in cold molecule physics. The optimum method for producing an intense, pulsed, supersonic beam of cold CH mole

APA, Harvard, Vancouver, ISO, and other styles

41

Pereira, Andrea Antunes. "Estudo de colisões inelásticas heteronucleares no sistema rubídio(Rb)/césio(Cs) em regimes de baixas temperaturas." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-09092008-123340/.

Full text

Abstract:

Armadilhamento duplo de átomos neutros constitui um dos avanços mais recentes no estudo de colisões frias. Obtivemos experimentalmente as taxas de perda devido a interação de espécies alcalinas mistas (Cs/Rb). Utilizamos uma armadilha magneto-óptica mista operando com feixes de alta intensidade permitindo o resfriamento e confinamento das amostras com sucesso. Esse trabalho apresenta-se de forma relevante pois corresponde a primeira etapa para o estudo do processo de formação de moléculas frias heteronucleares. Uma comparação entre duas técnicas de monitoramento dos processos de carga de átomo

APA, Harvard, Vancouver, ISO, and other styles

42

Dong, Jiaxin. "Impact of dynamin II domains on the function of dynamin II in vesicle formation at the trans Golgi network." [S.l.] : [s.n.], 2001. http://www.diss.fu-berlin.de/2001/72/index.html.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Lytle, Christian, and Christian Lytle. "Spectroscopy of Neutral Mercury in a Magneto-Optical Trap Based on a Novel Ytterbium Fiber-Amplified Cooling Laser Source." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/621471.

Full text

Abstract:

In this dissertation I present experimental results obtained on the mercury optical clock project in the research group of Jason Jones at the University of Arizona. The project began in 2008 with the purpose of investigating the feasibility of neutral mercury as an optical clock species. The first series of investigations involved building the essential apparatus and scanning the doppler-broadened 6¹S₀ - 6³P₀ clock transition in ¹⁹⁹Hg. Here I present significant modifications to the cooling and trapping laser, improvements to the spectroscopy laser linewidth, and attempts to measure the 2-phot

APA, Harvard, Vancouver, ISO, and other styles

44

SARKISSIAN, MARC. "Resultats fonctionnels des anastomoses colo-anales : a propos de 125 resections abdomino-trans-sphincteriennes pour cancer du rectum." Toulouse 3, 1990. http://www.theses.fr/1990TOU31523.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Henn, Emanuel Alves de Lima. "Variação da temperatura cinética em átomos aprisionados bombeados por campos externos." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-06062007-183559/.

Full text

Abstract:

Neste trabalho apresentamos o estudo da variação da temperatura cinética de átomos aprisionados magneticamente bombeados por campos eletromagnéticos externos. Aprisionamos átomos de Sódio em uma armadilha magnética de quadrupolo e submetemos esses átomos a um campo magnético externo oscilante. Medimos a temperatura e o número dos átomos remanescentes na armadilha a partir de imagens de tempo de vôo. O processo de medida consiste em desligar a armadilha, deixando a nuvem atômica expandir balisticamente e então fazer uma imagem da fluorescência desses átomos gerada por um pulso de luz próximo da

APA, Harvard, Vancouver, ISO, and other styles

46

Milori, Debora Marcondes Bastos Pereira. "Caracterização de uma armadilha magneto-optica para átomos de sódio em célula de vapor." Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-30042009-090336/.

Full text

Abstract:

Dentro as técnicas de controle do movimento atômico utilizando pressão de radiação, aprisionamento tem merecido maior destaque por produzir amostras de átomos mais frios (temperaturas da ordem de &#956K), com altas densidades e confinadas em pequenas regiões do espaço. Devido a essas motivações, tem sido grande o esforço para desenvolver e caracterizar estas armadilhas atômicas. Uma das mais eficientes armadilhas de átomos neutros construídas até agora é a armadilha magneto-óptica. O átomo uma vez capturado por este tipo de armadilha passa por um intenso processo de desaceleração via efeito Do

APA, Harvard, Vancouver, ISO, and other styles

47

Salas, Andres David Rodriguez. "Geração de uma armadilha magneto-óptica de estrôncio 88." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-05112012-155605/.

Full text

Abstract:

Neste trabalho é apresentada a construção da montagem de um sistema experimental para resfriar átomos de estrôncio. A construção do sistema está focada no estudo do espalhamento coletivo em nuvens atômicas frias e ultrafrias por meio da teoria de Mie. O estrôncio é um elemento que conta com dois estágios de resfriamento, o primeiro utilizando a transição forte entre estados singletos ¹S₀-¹P ₁ de Γ = (2 π)32 MHz, e o segundo com uma transição fraca entre estados singleto e tripleto ¹S₀-³P₁ de Γ = (2 π)7,5 MHz. O objetivo deste trabal

APA, Harvard, Vancouver, ISO, and other styles

48

Fritsch, Amilson Rogelso. "Montagem e caracterização de uma armadilha magneto-óptica de rubídio." Universidade do Estado de Santa Catarina, 2011. http://tede.udesc.br/handle/handle/2008.

Full text

Abstract:

Made available in DSpace on 2016-12-12T20:15:54Z (GMT). No. of bitstreams: 1 introducao.pdf: 91836 bytes, checksum: cb92c1e5e08cf2686a55fb3fdfcba785 (MD5) Previous issue date: 2011-07-20<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>In this work we present the building and characterization of a Magneto-Optical Trap (from now on named MOT) for Rubidium atoms. We perform experiments for studying the e¤ect of a broadband light over trapped atoms. In order to carry out this study we used a incandescent lamp which is broad in the wavelength spectrum. We observed in a MOT, with

APA, Harvard, Vancouver, ISO, and other styles

49

Garcia, Ferrer Irene. "Structural and functional studies on Escherichia coli alpha-2-macroglobulin: a snap- trap peptidase inhibitor." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/346636.

Full text

Abstract:

The balance between proteolytic and antiproteolytic activity is crucial in many biological processes such as nutrition, immune defence, virulence and tissue remodelling. Therefore, it is controlled by several mechanisms, among which by peptidic peptidase inhibitors that are encoded in the genomes of many organisms, representing up to 1% of genes in metazoa but being scarce and sketchy in bacteria. However, among bacterial peptidase inhibitors, some proteins with homology to the highly abundant metazoan a2-macroglobulins (a2Ms) have been described, which may have been acquired by bacteria from

APA, Harvard, Vancouver, ISO, and other styles

50

Silva, Ilde Guedes da. "Estruturas espaciais de átomos de Na em armadilha magneto-óptica." Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/54/54131/tde-21022014-101849/.

Full text

Abstract:

Neste trabalho demonstramos o confinamento de átomos de sódio usando a armadilha magneto-óptica, onde os átomos foram capturados diretamente a partir da distribuição inicial do vapor atômico a uma temperatura ambiente, contido em uma célula fechada. Observamos além da nuvem de átomos aprisionados, estruturas circulares em forma de anek, que surgem devido ao desalinhamento introduzido nos feixes de aprisionamento. Estudamos o comportamento do raio do anel em função de vários parâmetros utilizados na armadilha magneto-óptica como por exemplo: gradiente de campo magnético, intensidade do laser, d

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!