Dissertations / Theses on the topic 'Gases (Rare)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Gases (Rare).'
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.
Cunje, Alwin. "Noble gases and catalysis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0012/NQ59125.pdf.
Full textMcLaughlin, J. G. "Chemistry in liquid noble gases." Thesis, University of Nottingham, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356030.
Full textCryan, James. "A coincidence study of strong field ionization of rare gases." Connect to resource, 2007. http://hdl.handle.net/1811/25085.
Full textTitle from first page of PDF file. Document formatted into pages: contains 27 p.; also includes graphics. Includes bibliographical references (p. 27). Available online via Ohio State University's Knowledge Bank.
Morris, Gerald D. "Epithermal muons from solid rare-gas moderators." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29891.
Full textScience, Faculty of
Physics and Astronomy, Department of
Title page of the thesis missing.
Graduate
Leung, Ki Y. "Electron mobilities in binary rare gas mixtures." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29339.
Full textScience, Faculty of
Chemistry, Department of
Graduate
Hilton, D. R. "A study of hydrothermal systems using rare gas isotopes." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377843.
Full textCarman, R. J. "DC glow discharge electron guns for the excitation of rare gases." Thesis, University of St Andrews, 1986. http://hdl.handle.net/10023/14165.
Full textBroadhurst, Catherine Leigh. "Solubility and partitioning of noble gases in anorthite, diopside, forsterite, spinel, and synthetic basaltic melts: Implications for the origin and evolution of terrestrial planet atmospheres." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184935.
Full textHarmer, Muffin Louise Blakeney. "A dynamic model for calculating the uptake of an inhaled noble gas." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/21774.
Full textJun, Byung Soon. "Measurement of thermal accommodation coefficients of inert gas mixtures on a surface of stainless steel /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3025627.
Full textWightman, J. P. "Photoionisation studies of the rare gases and molecular deuterium using toroidal analysers." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270806.
Full textMadeira, Lucas 1991. "Many-body systems : heavy rare-gases adsorbed on graphene substrates and ultracold Fermi gases = Sistemas de muitos corpos: gases nobres pesados adsorvidos em substratos de grafeno e gases de Fermi ultrafrios." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276942.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
Made available in DSpace on 2018-08-28T00:18:16Z (GMT). No. of bitstreams: 1 Madeira_Lucas_M.pdf: 4273856 bytes, checksum: 8543c0dd916e2ec3fc638a5d31b32787 (MD5) Previous issue date: 2015
Resumo: Nessa dissertação nós investigamos dois sistemas de muitos corpos. Na primeira parte nós escolhemos uma abordagem clássica para estudar a adsorção de gases nobres pesados, Ne, Ar, Kr, Xe e Rn, em substratos de grafeno. Nós apresentamos evidências de camadas adsorvidas comensuradas, as quais dependem fortemente da simetria do substrato, para duas estruturas: camadas de Ne na rede sqrt{7} X sqrt{7} e Kr na rede sqrt{3} X sqrt{3}. Para estudar o derretimento nós introduzimos um parâmetro de ordem e sua susceptibilidade. O calor específico e a susceptibilidade em função da temperatura foram calculados para os gases nobres pesados em diversas densidades. A posição e largura característica dos picos do calor específico e da susceptibilidade foram determinadas. Finalmente, nós investigamos a distância dos primeiros vizinhos e a distância entre a camada e o substrato, identificando contribuições relacionadas aos picos do calor específico e da susceptibilidade. A segunda parte da dissertação trata de uma linha de vórtice no gás unitário de Fermi. Gases fermiônicos ultrafrios são notáveis devido à possibilidade experimental de variar as interações interpartículas através de ressonâncias de Feshbach, o que possibilita a observação do crossover BCS-BEC. No meio do crossover encontra-se um estado fortemente interagente, o gás unitário de Fermi. Uma linha de vórtice corresponde a uma excitação desse sistema com unidades de circulação quantizadas. Nós construímos funções de onda, inspiradas na função BCS, para descrever o estado fundamental e também o sistema com uma linha de vórtice. Nossos resultados para o estado fundamental elucidam aspectos da geometria cilíndrica do problema. O perfil de densidade é constante no centro do cilindro e vai a zero suavemente na borda. Nós separamos a contribuição devido à parede da energia do estado fundamental e determinamos a energia por partícula do bulk, epsilon_0=(0.42 +- 0.01) E_{FG}. Nós também calculamos o gap superfluído para essa geometria, Delta=(0.76 +- 0.01) E_{FG}. Para o sistema com a linha de vórtice nós obtivemos o perfil de densidade, o qual corresponde a uma densidade não nula no centro do vórtice, e a energia de excitação por partícula, epsilon_{ex}=(0.0058 +- 0.0003) E_{FG}. Os métodos empregados nessa dissertação, Dinâmica Molecular, Monte Carlo Variacional e Monte Carlo de Difusão, nos dão uma base sólida para a investigação de sistemas relacionados, e outros sistemas, de muitos corpos no futuro
Abstract: In this dissertation we investigated two many-body systems. For the first part we chose a classical approach to study the adsorption of heavy rare-gases, Ne, Ar, Kr, Xe and Rn, on graphene substrates. We presented evidences of commensurate adlayers, which depend strongly on the symmetry of the substrate, for two structures: Ne adlayers in the sqrt{7} X sqrt{7} superlattice and Kr in the sqrt{3} X sqrt{3} lattice. In order to study the melting of the system we introduced an order parameter, and its susceptibility. The specific heat and susceptibility as a function of the temperature were calculated for the heavy noble gases at various densities. The position and characteristic width of the specific heat and susceptibility peaks of these systems were determined. Finally, we investigated the first neighbor distance and the distance between the adlayer and the substrate, identifying contributions related to specific heat and melting peaks. The second part of the dissertation deals with a vortex line in the unitary Fermi gas. Ultracold Fermi gases are remarkable due to the experimental possibility to tune interparticle interactions through Feshbach resonances, which allows the observation of the BCS-BEC crossover. Right in the middle of the crossover lies a strongly interacting state, the unitary Fermi gas. A vortex line corresponds to an excitation of this system with quantized units of circulation. We developed wavefunctions, inspired by the BCS wavefunction, to describe the ground state and also for a system with a vortex line. Our results for the ground state elucidate aspects of the cylindrical geometry of the problem. The density profile is flat in the center of the cylinder and vanishes smoothly at the wall. We were able to separate from the ground state of the system the wall contribution and we have determined the bulk energy as epsilon_0=(0.42 +- 0.01) E_{FG} per particle. We also calculated the superfluid pairing gap for this geometry, Delta=(0.76 +- 0.01) E_{FG}. For the system with a vortex line we obtained the density profile, which corresponds to a non-zero density at the core, and the excitation energy, epsilon_{ex}=(0.0058 +- 0.0003) E_{FG} per particle. The methods employed in this dissertation, Molecular Dynamics, Variational Monte Carlo and Diffusion Monte Carlo, give us a solid basis for the investigation of related and other many-body systems in the future
Mestrado
Física
Mestre em Física
2012/24195-2
FAPESP
Bargheer, Matias. "Ultrafast photodynamics in condensed phase ClF, Cl2 and I2 in solid rare gases /." [S.l. : s.n.], 2002. http://www.diss.fu-berlin.de/2002/206/index.html.
Full textWang, Liping, and lwang@it swin edu au. "Three-body effects on the phase behaviour of noble gases from molecular simulation." Swinburne University of Technology. Centre for Molecular Simulation, 2005. http://adt.lib.swin.edu.au./public/adt-VSWT20060608.145124.
Full textDiChiara, Anthony D. "Ionization measurements of argon, krypton and xenon atoms with petawatt- to exawatt-per-square-centimeter laser fields /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 178 p, 2008. http://proquest.umi.com/pqdweb?did=1459933361&sid=13&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full textHirst, G. "Ionic species in gas lasers." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379854.
Full textHedin, Lage. "Studies of Single and Multiple Ionization Processes in Rare Gases and some Small Molecules." Doctoral thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-221128.
Full textVan, Heest Timothy Milner. "Identification of metal-organic framework materials for adsorptive separation of the rare gases: applicability of IAST and effects of inaccessible regions." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43715.
Full textBarrios, Andrés J. "Yield of metastable atoms from a rare gas discharge in a longitudinal magnetic field." FIU Digital Commons, 1993. http://digitalcommons.fiu.edu/etd/1415.
Full textRaston, Paul L. "Spectroscopy and dynamics of rare gas and chlorine atoms in solid hydrogen." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1338905001&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
Full textHamme, Roberta Claire. "Applications of neon, nitrogen, argon, and oxygen to physical, chemical, and biological cycles in the ocean /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/10997.
Full textGibson, Hubert C. "Gaseous swelling and release in nuclear fuels during grain growth." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49103.
Full textDay, Brian Scott. "The Dynamics of Gas-Surface Energy Transfer in Collisions of Rare Gases with Organic Thin Films." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29860.
Full textPh. D.
CARVALHO, MARCOS R. de. "Metodologia para determinacao da eficiencia de um monitor de gases emissores de particulas beta." reponame:Repositório Institucional do IPEN, 1995. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10662.
Full textMade available in DSpace on 2014-10-09T14:07:53Z (GMT). No. of bitstreams: 1 04994.pdf: 5757270 bytes, checksum: 17538e0c134d27fb78f39d761d00b604 (MD5)
Dissertacao(Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
Foster, Kathleen. "Design of an inlet line monitor system for the state of Illinois gaseous effluent monitoring system." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17323.
Full textIorio, Carlo Saverio. "Experimental and numerical study of the coupling between evaporation and thermocapillarity preparation of the Cimex-1 experiment." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210836.
Full textThe present work has been organized in two main parts: in the first one, the focus will be on the scientific and theoretical aspects of the evaporation process in presence of an inert gas flow while in the second all the technical aspects and more practical tests related to the real implementation of the micro-gravity experiment CIMEX-1 will be detailed. In any cases, the discussion will always start from the phenomenology observed considering that ” Nature is far more reach of any speculations.”
Part I: Evaporation in presence of inert gas
In chapter 1, a detailed presentation of the experimental setups for the on-ground tests is given together with the presentation of the qualitative and quantitative results obtained. Actually, the main parameters that regulate such kind of experiments are the mass flow rate of inert gas, the total pressure of the cell and the geometrical shape and dimensions of the evaporating regions.
Consequently, the experiments aimed at covering the maximal possible combination of these three parameters with special attention to the variation of the inert gas flow and of the thickness of the evaporating liquid layer. More precisely, the liquid layer thickness was in the range 1.2 to 3.8 mm while the inert gas flow was set in the range 50 to 2500 ml/min. The pressure has been partially neglected as control parameter because its control was discovered not to be very reliable.
The visualization system used in all the experiments consisted in a opportunely calibrated infrared camera. It allowed for having a quantitative analysis of the temperature distribution at the interface of the evaporating liquid.
The infrared images also helped to follow the thermal history of the interface. In many cases, it has been possible to clearly observe the evolution of instability patterns at the interface that represent an original contribution to the understanding of such a kind of phenomena.
The physical and mathematical modeling of the observed phenomenology will be the subject of the chapter 2. One of the peculiar issue of the problem under consideration is that the thermal gradient normal to the interface is not directly imposed like in the usual Marangoni-Bénard experience, but is a result of the cooling of the interface due to the evaporation.
Moreover,the interface is subject to the shear stress of the inert gas flow and to the one due to the thermo-capillarity. Finally, the gas phase is to be considered as a mixture; this oblige to solve a diffusion problem in the gas phase. A physical model that takes into account the different aspects mentioned above is presented together with the governing equations and the appropriate boundary conditions.
Numerical issues involved in solving the model are also analyzed. Numerical results obtained are finally discussed and compared when possible with experimental results.
Part II: Preparation of the CIMEX-1 experiment on-board the International Space Station.
In chapter 3, we will describe the main platforms used to perform low-gravity experiments. They will be classified according to the low-gravity level and to the low-gravity interval duration that could be ensured for experiments. According to these criteria, the list of the low-gravity platforms will be as follows: Drop Towers with ≈ 4 sec. of micro-gravity, Parabolic Flights that can assure not more than ≈ 25 sec. Sounding Rockets with a low-gravity time of the order of several minutes depending on the rockets, Foton Capsules that assure for many days of high quality - i.e. without perturbations - low-gravity level and ,last but not least, the International Space Station where the low-gravity duration could be even of several weeks which is a sufficient time duration for the most part of the experiments.
The chapter 4 will be entirely devoted to the ITEL experiment that is the precursor and the core of the CIMEX-1. After a brief overview of the experiment that has been performed twice on-board sounding rockets of the MASER class, the experimental setups used both on-ground and in micro-gravity will be detailed.
The focus will be on the experimental results obtained on-ground during the preparatory tests and during the two sounding rocket flights with special attention to the first one. The analysis will be supported by the presentation of many results obtained in numerical simulations.
The two parabolic flight campaigns performed to test one of the key sub-systems of the CIMEX-1 setup are the subject of the chapter 5. The separating-condensing unit is mandatory for performing the experiment on-board the International Space Station because the limitations on the crew intervention oblige to have a closed loop experiment.
The goal of the two parabolic flights will be detailed together with the setup and the experimental scenario. The main results will be also shown and some considerations on the efficiency of the system will be presented.
It is worthy to stress that the results obtained during these parabolic flights have been determinant at the European Space Agency level to fly the CIMEX-1 experiment on-board the International Space Station.
Finally, in the section conclusions and perspectives the main results obtained will be summarized together with the new scenarios opened by the present work and some guidelines for further development in the experimental, theoretical and technical analysis.
Doctorat en sciences appliquées
info:eu-repo/semantics/nonPublished
Govers, Kevin. "Atomic scale simulations of noble gases behaviour in uranium dioxide." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210509.
Full textat elevated burnups, where large amounts of gas are produced and can
potentially be released. The importance of fission gas release was the motivation
for large efforts, both experimentally and theoretically, in order to increase our
understanding of the different steps of the process, and to continuously improve
our models.
Extensions to higher burnups, together with the growing interest in novel types
of fuels such as inert matrix fuels envisaged for the transmutation of minor actinides,
make that one is still looking for a permanently better modelling, based
on a physical understanding and description of all stages of the release mechanism.
Computer simulations are nowadays envisaged in order to provide a better
description and understanding of atomic-scale processes such as diffusion, but even
in order to gain insight on specific processes that are inaccessible by experimental
means, such as the fuel behaviour during thermal spikes.
In the present work simulation techniques based on empirical potentials have
been used, focusing in a first stage on pure uranium dioxide. The behaviour of
point defects was at the core of this part, but also the estimation of elastic and
melting properties.
Then, in a second stage, the study has been extended to the behaviour of helium
and xenon. For helium, the diffusion in different domains of stoichiometry
was considered. The simulations enabled to determine the diffusion coefficient and
the migration mechanism, using both molecular dynamics and static calculation
techniques. Xenon behaviour has been investigated with the additional intention
to model the behaviour of small intragranular bubbles, particularly their interaction
with thermal spikes accompanying the recoil of fission fragments. For that
purpose, a simplified description of these events has been proposed, which opens
perspectives for further work.
/
Les performances du combustible nucléaire sont fortement affectées par le comportement
des gaz de fission, et ce particulièrement lorsqu’un taux d’épuisement
élevé est atteint, puisque d’importantes quantités de gaz sont alors produites
et peuvent potentiellement être relâchées. Les enjeux, entre autre économiques,
liés au relâchement de gaz de fission ont donné lieu à d’importants efforts, tant
sur le plan expérimental que théorique, afin d’accroître notre compréhension des
différentes étapes du processus, et d’améliorer sans cesse les mod`eles. Les extensions
à des taux d’épuisements encore plus élevés ainsi que l’intérêt croissant pour
de nouveaux types de combustible tels que les matrices inertes, envisages en vue
de la transmutation des actinides mineures, font qu’à l’heure actuelle, le besoin
permanent d’une meilleure modélisation, basée sur une compréhension et une description
physique des différentes étapes du processus de relâchement de gaz de
fission, est toujours de mise.
Les simulations par ordinateur ont ainsi été considérée comme un nouvel angle
de recherche sur les processus élémentaires se produisant à l’échelle atomique, à la
fois afin d’obtenir une meilleure compréhension de processus tels que la diffusion
atomique ;mais aussi afin d’avoir accès à certains processus qui ne sont pas observables
par des voies expérimentales, tels que la le comportement du combustible
lors de pointes thermiques.
Dans ce travail, deux techniques, basées sur l’utilisation de potentiels interatomiques
empiriques, ont permis d’étudier le dioxyde d’uranium, dans un premier
temps en l’absence d’impuretés. Cette partie était principalement centrée sur le
comportement des défauts ponctuels, mais a aussi concerné différentes propriétés
élastiques, ainsi que le processus de fusion du composé.
Ensuite l’étude a été étendue aux comportements de l’hélium de du xénon. Pour
ce qui a trait à l’hélium, la diffusion dans différents domaines de stoechiométrie
a été considérée. Les simulations ont permis de déterminer le coefficient de diffusion
ainsi que le mécanisme de migration lui-même. Quant au xénon, outre les
propriétés de diffusion, l’intention fut de se diriger vers la modélisation des petites
bulles intragranulaires, et plus précisément vers leur interaction avec les pointes
thermiques, créées lors du recul des fragments de fission. Une description simplifiée de ce processus a été proposée, qui offre de nouvelles perspectives dans ce
domaine.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Toczyłowski, Rafał R. "From noble gas dimers to nucleic acid base pairs studies of weak intermolecular interactions /." Oxford, Ohio : Miami University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1102106714.
Full textSpringate, Emma Louise. "Atomic clusters in intense laser fields." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313391.
Full textSpratt, David James. "Electron loss and excitation in atom-atom collisions." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287429.
Full textOliveira, Junior Myriano Henriques de. "Efeitos da pressão exercida por uma matriz de carbono em átomos de xenônio." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277835.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
Made available in DSpace on 2018-08-04T16:01:42Z (GMT). No. of bitstreams: 1 OliveiraJunior_MyrianoHenriquesde_M.pdf: 3252159 bytes, checksum: a130bcbe767628c40a0600e14112a2a4 (MD5) Previous issue date: 2005
Resumo: Neste trabalho foi preparada uma série de filmes de carbono amorfo pelo processo de IBAD (Ion Beam Assisted Deposition), onde foi utilizado um feixe iônico de Xe com energia fixa para todas as amostras em 1500eV para realizar sputtering em um alvo de grafite e, um segundo feixe de Xe + responsável pelo bombardeio do filme durante o crescimento. Para cada amostra foi utilizada uma energia de bombardeio diferente, de 0 a 400eV. Esse bombardeio, além de gerar uma compactação da matriz induzindo uma pressão na rede (stress intrínseco), faz com que uma certa quantidade de Xe seja incorporada pelo filme. Por medidas de RBS foram observadas concentrações de 3 a 4% desse gás nobre na matriz, que são as concentrações nas quais são observadas formações de aglomerados sólidos desse elemento quando implantado em metais ou semicondutores cristalinos. Por medidas de XAS realizadas com radiação com energias no intervalo que envolve a borda L3 do xenônio foi verificada a formação de tais aglomerados sólidos e, em conjunto com resultados obtidos por simulações computacionais obtivemos um entendimento melhor sobre a estrutura fina na região de XANES dessa borda de absorção. A partir da técnica de SAXS foram encontradas estruturas com dimensões características de cerca de 10 a 25nm de forma achatada. Como os filmes de a-C crescidos por essa técnica são altamente grafíticos, contendo uma concentração de cerca de 90% de ligações do tipo sp 2 essas estruturas parecem ser aglomerados grafíticos, cujas dimensões mostraram-se dependentes da energia de bombardeio utilizada na deposição
Abstract: In this work it was prepared a series of amorphous carbon thin films using the ion beam assisted deposition technique. We used a xenon ion beam in order to sputter a graphite target with a fixed energy of 1500eV for all samples set up. A second ion beam was used as an ion assisting beam during the deposition with different energy for each film but, always in the range of 0 to 400eV. As the bombardment energy is varied the film produced can have a structure more or less compact which implies in a pressure rising along the amorphous net, called intrinsic stress. Another consequence of the bombardment is the xenon incorporation. By RBS measurements it was observed a concentration of about 3 to 4% of this noble gas inside the films, which belong to the same range where is observed a condensation of this element in solid clusters when implanted in crystalline metals or semiconductors. From XAS measurements, with radiation energy within a range involving the Xe L3 absorption edge, those solid clusters formation were observed. With some computational simulations compared to those experimental results we were able to have a better comprehension about XANES fine structure. We used SAXS measurements to try to determine some geometrical parameters beyond those obtained by XAS. As the xenon clusters dimensions are too small (probably of about ten atoms) it is difficult to detect them by this technique with the experimental parameters used but, it was observed some structures that seem to be shaped and have characteristics dimensions varying from 10 to 25nm. What seem to be graphitic planes clusters, once amorphous carbon thin films prepared by IBAD are graphitic-like
Mestrado
Física da Matéria Condensada
Mestre em Física
Koči, Love. "Studies of Material Properties using Ab Initio and Classical Molecular Dynamics." Doctoral thesis, Uppsala universitet, Kondenserade materiens teori (Fysik IV), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8626.
Full textKint, Mathieu. "Elasticité de la silice vitreuse sous pression de gaz rares." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS242/document.
Full textWe present an in situ study of vitreous silica v-SiO2 under hydrostatic noble gases pressure by Brillouin and Raman spectroscopy. Samples are pressurized in helium, neon and argon in a diamond anvil cell, in the range 0 - 8 GPa. Helium and neon atoms penetrate in the pressurized glass structure. We estimate that about one atom of helium per SiO4 tetrahedron and about half in the neon case are adsorbed at 6 GPa. Bulk and shear moduli as a function of fluid pressure are obtained from measurements of the longitudinal and transverse acoustic velocities. The behaviour anomaly of the bulk modulus of v-SiO2 (minimum at 2 GPa) is suppressed by He and Ne adsorption, structural rearrangements associated with this anomaly being prevented by the occupation of interstitial sites by helium and neon atoms. In the presence of helium and neon, the V(P) equation of state does not allow to recover bulk modulus because silica behaves like an open porous medium. Monte-Carlo simulation of adsorption isotherms combined with the generalized theory of poromechanics allows to describe volume deformations and adsorbed fluid amount in agreement with experimental results. In the neon case, adsorption-desorption kinetics is observed by Brillouin spectroscopy. Measurements of VV and VH Raman spectra of v-SiO2 are made as function of fluid pressure. The reduction of Si–O–Si angles distribution is prevented by the insertion of helium
Sun, Xue-Zhong. "Fast infrared spectroscopy in supercritical fluids." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311743.
Full textHofmann, Martin Alexander [Verfasser], Lothar [Akademischer Betreuer] Oberauer, Andreas [Akademischer Betreuer] Ulrich, and Hubert [Akademischer Betreuer] Kroha. "Liquid Scintillators and Liquefied Rare Gases for Particle Detectors : Background-Determination in Double Chooz and Scintillation Properties of Liquid Argon / Martin Alexander Hofmann. Gutachter: Andreas Ulrich ; Lothar Oberauer ; Hubert Kroha. Betreuer: Lothar Oberauer." München : Universitätsbibliothek der TU München, 2012. http://d-nb.info/1031075305/34.
Full textHashimoto, Yumi Rocha. "Avaliação da concentração de radônio em casas pré-fabricadas e determinação da camada emissora de radônio em argamassa de cimento." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2856.
Full textRadon-related research is required because of the carcinogenic potential of this gas, and the reference limits are subject of recommendations. For this research, radon concentrations were measured inside and outside of two prefabricated houses, built in an experimental environment, in UTFPR/Ecoville. One of these houses was built with building materials from the Czech Republic (1) and the other (2) with materials from Brazil. Whith this proposal, 40 CR-39 detectors were used. The average concentration for house (1) was 10,1±1,3 Bq/m³, for house (2) was 7,8±1,1 Bq/m³ and for the exterior was 11,5±2,9 Bq/m³. The values obtained were below 300 Bq/m³, thus, no mitigating measures were necessary. Besides, measurements were made of the number of thacks of alpha particles coming from common cement paste samples and from sand with high radon activity samples in order to identify the value of the emitting layer. For common cement paste samples of 1.5, 2.6, 3.8 and 4.6 cm of thickness, the number os tracks was 762±25, 799±51, 814±31, 791±45 e 798±27, respectively. The analysis showed that there ir no statistical difference between the data, which indicates that the thickness of 1.5 cm is already configured as a limit for a randon exhalation. For the active sand samples of 1.4, 2.3, 2.9, 3.5 and 4.2 cm, the number of tracks was 380±18, 322±15, 298±5, 548±25 e 446±83, respectively. In a general analysis, it was concluded that there is no expressive increase of the exhalation with the increase of the thickness, só that the thickness of 1.4 cm is already configured as a limit for the exhalation of radon. In order to determine the concentration of radon exhaled by the samples made of common cement past and active sand, were analyzed samples in flasks where the secular equilibrium had already occured. The results showed that, for common cement past samples, the values do not represent and expressive growth. However, for the test samples with high radon activity and increase in the concentration with increasing the thickness was observed. To determine the contribution of the concentrations in an indoor environment, radon exhalation flux measurement was performed. These results were extrapolated to the standard room and varies from 15 to 60 Bq/m³. This contribution can be considered expressive, but not of concern, só the results were considered close to normality.
Stanley, Rachel H. R. "A determination of air-sea gas exchange and upper ocean biological production from five noble gasses and tritiugenic helium-3." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42282.
Full textIncludes bibliographical references (p. 215-225).
The five noble gases (helium, neon, argon, krypton, and xenon) are biologically and chemically inert, making them ideal oceanographic tracers. Additionally, the noble gases have a wide range of solubilities and molecular diffusivities, and thus respond differently to physical forcing. Tritium, an isotope of hydrogen, is useful in tandem with its daughter helium-3 as a tracer for water mass ages. In this thesis, a fourteen month time-series of the five noble gases, helium-3 and tritium was measured at the Bermuda Atlantic Time-series Study (BATS) site. The time-series of five noble gases was used to develop a parameterization of air-sea gas exchange for oligotrophic waters and wind speeds between 0 and 13 m s-1 that explicitly includes bubble processes and that constrains diffusive gas exchange to ± 6% and complete and partial air injection processes to ± 15%. Additionally, the parameterization is based on weeks to seasonal time scales, matching the time scales of many relevant biogeochemical cycles. The time-series of helium isotopes, tritium, argon, and oxygen was used to constrain upper ocean biological production. Specifically, the helium flux gauge technique was used to estimate new production, apparent oxygen utilization rates were used to quantify export production, and euphotic zone seasonal cycles of oxygen and argon were used to determine net community production. The concurrent use of these three methods allows examination of the relationship between the types of production and begins to address a number of apparent inconsistencies in the elemental budgets of carbon, oxygen, and nitrogen.
by Rachel H.R. Stanley.
Ph.D.
Rosa, Cinara Ewerling da. "FORMULACÃO UNIFICADA PARA MODELOS CIN�ETICOS DERIVADOS DA EQUAÇÃO DE BOLTZMANN COM CONDIÇÕES DE CONTORNO GENERALIZADAS." Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/9974.
Full textIn this paper, we present numerical results obtained from the FORTRAN language for physical quantities of interest such as velocity profile, pro�le, heat ow rate, particle ow rate,heat ux and pressure tensor component. The gas ow occur in the direction parallel to thesurface the gas is confined because of a constant gradient of pressure and a constant gradient of temperature are represented by Poiseuille Problem and Problem Creep Thermal, respectively. It also considers the Couette Problem where the gas moves from the motion of the plates in opposite directions. In order to describe the gas-surface interaction we use the kernel of Cercignani-Lamp, which as opposed to core scattering Maxwell has two accommodation coeficients to represent the physical properties of gas, leaving this interaction closer to reality. From the simplification of the Boltzmann equation has the kinetic theory for rarefied gas dynamics, which is developed analytically in a uni�ed approach to the BGK Model, S Model, Gross-Jackson (GJ) Model and MRS Model. Thus, we seek to model that most closely approximates the veracity, comparing the numerical values generated by the models and the linearized Boltzmann equation through numerical analysis, graphics and mathematical statistics with the procedure of the variance of two factors made by Friedman. A version of the analytical method of discrete ordinates (ADO) is used to solve the problems of Poiseuille, Creep Thermal and Couette for two plates infinte paralalelas with different chemical constitutions Boundary Conditions for the Cercignani-Lampis.
Neste trabalho, são apresentados resultados numéricos obtidos a partir da linguagem FORTRAN para quantidades físicas de interesse como perfil de velocidade, perfil fluxo de calor, taxa fluxo de partícula, taxa fluxo de calor e componente tensor de pressão. O fluxo gasoso ocorre na direção paralela a superfície que o gás esta confinado devido a um gradiente constante de pressão e um gradiente constante de temperatura que são representados pelo Problema de Poiseuille e Problema Creep térmico respectivamente. Além disso, também considera-se o Problema de Couette onde o gás se move a partir do movimento das placas em sentidos opostos. A �fim de descrever a interação gás-superfície utiliza-se o núcleo de Cercignani-Lampis, que ao contrário do núcleo de espalhamento de Maxwell tem dois coeficientes de acomodação para representar as propriedades físicas do gás, deixando esta interação mais próxima da realidade. A partir da simplificação da Equação de Boltzmann tem-se a teoria cinética para a dinâmica de gases rarefeito, que é desenvolvida analiticamente em uma abordagem unificada para o Modelo BGK, Modelo S, Modelo Gross-Jackson (GJ) e Modelo MRS. Dessa maneira, busca-se o modelo que mais se aproxima da veracidade, comparando os valores numéricos gerados pelos modelos e a Equação Linearizada de Boltzmann através de análises numéricas, gráficas e de matemática estatística com o procedimento da variância de dois fatores de Friedman por postos. Uma versão analítica do método de ordenadas discretas (ADO) é usada para resolver os Problemas de Poiseuille, Creep Térmico e Couette para duas placas paralalelas infintas com constituições químicas diferentes para Condições de Contorno de Cercignani-Lampis.
Hemici, Mustapha. "Spectroscopie laser sur niveaux électroniques excités d'excimères et d'ions de gaz rares." Saint-Etienne, 1994. http://www.theses.fr/1994STET4015.
Full textRossomme, Séverine. "Modélisation de l'évaporation des films liquides minces, y compris au voisinage des lignes de contact: application aux caloducs à rainures." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210409.
Full textL’étude décrite dans la première partie propose une contribution originale à la modélisation de l’évaporation des films minces, y compris au voisinage des lignes de contact. De manière générale, nous cherchons à mettre en évidence l’influence de phénomènes qui se déroulent aux petites échelles sur le transfert thermique d’un film mince déposé sur une paroi plane et chauffée. Dans le cadre de l’hypothèse de lubrification, deux modèles sont dès lors développés. Le premier modèle décrit l’évaporation d’un film liquide mince dans sa vapeur pure tandis que le second modèle porte sur l’évaporation d’un film liquide mince dans un gaz inerte. Les diverses recherches menées sont principalement orientées vers la quantification, d’une part, des angles de contact apparents générés par l’évaporation, malgré le caractère parfaitement mouillant du couple liquide-solide utilisé et, d’autre part, des flux de chaleur et de matière interfaciaux. Une particularité du premier modèle est qu’il généralise divers modèles existants [15,25,86,117] en regroupant un ensemble de phénomènes spécifiques et complexes tels que le saut de température à l’interface liquide-vapeur, la résistance thermique de la vapeur et celle du solide ou la variation locale de la température de saturation à l’interface liquide-vapeur suite à la courbure interfaciale et aux forces de van der Waals. En plus de ces effets, d’autres mécanismes plus classiques sont inclus dans le modèle :la tension superficielle, la thermocapillarité, la pression de disjonction, l’évaporation et le recul de vapeur. Des analyses de stabilité linéaires et des études paramétriques ont été réalisées afin de quantifier l’influence de ces phénomènes sur la stabilité d’un film liquide mince, sur son évaporation et sur le transfert de chaleur associé. Au travers des chapitres 3 et 4, nous mettons notamment en évidence
• comment les forces de van der Waals compensent l’évaporation du film liquide mince de façon à créer un film stationnaire stable,
• pourquoi le recul de la vapeur et la thermocapillarité sont deux phénomènes qui peuvent être négligés dans les conditions étudiées dans ce travail,
• des lois analytiques qui décrivent certaines variables du problème, plus particulièrement l’angle de contact et le maximum du flux de chaleur, en fonction de la surchauffe de la paroi solide.
Faisant suite aux travaux proposés par Haut et Colinet [59], nous avons ensuite développé un second modèle afin de caractériser l’évaporation dans une faible quantité de gaz inerte d’un film liquide mince déposé sur une paroi plate et chauffée. Tout comme dans le cadre de l’étude précédente, notre analyse s’articule autour d’une étude de stabilité linéaire ainsi que d’études paramétriques réalisées sur des nombres caractéristiques du problème. Alors que les conclusions sur la stabilité du film sont indépendantes de la quantité de gaz inerte contenue dans la phase vapeur, il n’en est pas de même pour les transferts de matière et de chaleur interfaciaux comme montré au chapitre 5.
Dans la seconde partie du travail, nous utilisons les conclusions auxquelles nous sommes arrivés dans la première partie dans le cadre d’une application industrielle. En collaboration avec le Centre d’Excellence en Recherche Aéronautique (CENAERO) et la société Euro Heat Pipes (EHP), une stratégie a été élaborée afin de simuler les transferts thermiques radiaux dans une rainure d’un caloduc au niveau de l’évaporateur. Les résultats numériques, obtenus sur base d’un modèle multi-échelle développé à l’ULB et implémenté numériquement lors d’un stage chez CENAERO, montrent que ces transferts sont influencés par la valeur de l’angle de contact. Celui-ci dépendant des phénomènes microscopiques, il s’avère par conséquent nécessaire de les inclure dans le modèle thermique. En effet, si nous ne considérons que les aspects macroscopiques du problème, qui se résument à la conduction dans le solide et dans le liquide, le coefficient d’échange global au niveau de la rainure est surestimé.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
SOUZA, EDVALDO R. de. "Caracterizações microestruturais e avaliações das propriedades mecânicas das juntas em aço inoxidável AISI 301 L soldadas por MIG e submetidas ao reparo pelo processo TIG." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26797.
Full textMade available in DSpace on 2016-11-11T09:40:30Z (GMT). No. of bitstreams: 0
A soldagem tem grande importância no setor metroferroviário, pois é empregada na fabricação de componentes estruturais e no acabamento de vagões de passageiros, que em sua maior parte são de aço inoxidável. As juntas soldadas podem apresentar descontinuidades que são interrupções que afetam as propriedades mecânicas e metalúrgicas da junta soldada. A presença destas descontinuidades, dependendo do seu tamanho, natureza ou efeito combinado, pode ocasionar a reprovação da junta soldada, quer pela redução de propriedades mecânicas ou pela não aceitação, segundo critérios estabelecidos em normas. Uma estrutura que tenha uma solda reprovada durante sua qualificação ou inspeção, pela presença de descontinuidades pode ser recuperada, por meio de um retrabalho a ser realizado nesta junta. A refusão do cordão de solda por meio do processo TIG (Tungsten Inert Gas), sem a utilização do material de adição, é uma técnica de retrabalho que pode ser empregada, em especial pela viabilidade técnica e econômica do processo. Neste estudo analisou-se a influência que o processo de reparo por soldagem TIG exerceu no comportamento mecânico e microestrutural das juntas soldadas pelo processo MIG, por meio de: ensaios mecânicos (tração, fadiga e microdureza Vickers), ensaios não destrutivos (inspeção visual e líquidos penetrantes) e caracterização microestrutural do cordão de solda. Resultados das amostras de ensaio de tração e fadiga indicaram que o reparo dos cordões de solda não alterou o comportamento mecânico das juntas. As juntas submetidas ao reparo nas quais foram retirados os reforços dos cordões apresentaram modificações nas propriedades mecânicas, mas também apresentaram resultados satisfatórios.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Chamorro, Perez Eva Maria. "Les volatils dans le manteau terrestre : étude expérimentale à haute pression et haute température ; l'exemple de l'argon et du carbone." Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10178.
Full textAvice, Guillaume. "Origin and evolution of atmospheric xenon and other noble gases : geodynamical and atmospheric implications." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0032/document.
Full textThe origin of the Earth's atmosphere remains poorly understood. Its elemental and isotopic compositions have been shaped by numerous events in the history of our planet, such as extraterrestrial contributions, mantle degassing, atmospheric escape etc. This study aimed to analyze the composition of atmospheric gases trapped in several billion years old samples in order to better understand the origin and evolution of the Earth's atmosphere. Isotope analyses of xenon, a noble gas, demonstrate that part of the atmosphere was not brought by meteorites but might have been delivered to the Earth's atmosphere by volatile-rich bodies such as comets. Furthermore, the isotopic composition of atmospheric Xe evolved over geological ages and can be linked to the progressive oxidation of the atmosphere that permitted the emergence and development of modern forms of life
Miller, Jonathan Robert. "The effect of solution uptake rate on aerosol characteristics and signal emission intensities for inductively coupled plasma-atomic emission spectroscopy." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/30387.
Full textCaracausi, Antonio. "Noble gases as geochemical tracers of Earth's dynamic and evolution." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0339.
Full textIn my project, I used the nobles gases (He, Ne, Ar, Kr and Xe) to investigate natural processes occurring in different geodynamical contexts (i.e., subduction, continental collision, rifting), showing how the use of the noble gases is fundamental to constrain the origin of volatiles, and to investigate the Earth interior. Furthermore, I also used these volatiles to recognize the processes (water-gas-rock interaction) that occur during the fluids up rise from the Earth’s interior to the atmosphere and quantitatively constrain the extents of these processes. The results of my project are summarized in five main topics: 1) Insights into the degassing history of Earth’s mantle from high precision noble gas analysis of magmatic gas 2) Noble Gas and Carbon Isotope Systematics at the Seemingly Inactive Ciomadul Volcano (Romania): Evidence for Volcanic Degassing 3) Mantle‐Derived Fluids in the East Java Sedimentary Basin, Indonesia 4) Outgassing of Mantle Volatiles in Compressional Tectonic Regime Away From Volcanism: The Role of Continental Delamination 5) Continental degassing of helium in an active tectonic setting (northern Italy): the role of seismicity
Smith, Thomas. "Transfert vertical des gaz rares à l'échelle des différentes formations de la zone de transposition du site Meuse/Haute-Marne et à l'échelle des eaux porales de l'argilite du Callovo-Oxfordien." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14127/document.
Full textThe French Radioactive Waste Management National Agency (Andra) is studying the possibility of a high level and long lived radioactive waste repository in geological formation. Since 1994, Andra is studying the properties of the Callovo-Oxfordian (COx) argillaceous rock, located in the eastern part of the Paris Basin. In the designated zone, COx is a 130 meters thick clay rich sequence, found at a depth of about 500 meters and encompassed between two aquifers, the Oxfordian limestone above and the Dogger limestone below. Callovo-Oxfordian permeabilities are very low, which is suitable with radioactive waste disposal. Noble gases (He, Ne, Ar, Kr and Xe) are considered as natural tracers, useful in hydrogeology, for several reasons. First, noble gases are nearly chemically inert, and then no reaction occurs between them and other species. Secondly, noble gases have several isotopes and many of them have different origins, so it is possible to distinguish sources terms. Noble gases concentrations in geological formations are controlled by physical properties such as temperature, pressure and salinity. To have more information on the COx properties, Andra has selected four drilling sites in a 250 km2 area around the Underground Research Laboratory. From November 2007 to June 2008, on each site, Callovo-Oxfordian clay and both overlaying (Oxfordian) and underlying (Dogger) limestones were investigated. A 1600 meters deep borehole, reaching the Trias base, allows investigating the whole length of the Mesozoïc sedimentary pile.On each drilling sites (named A, B, C and D), pore water noble gases concentrations were performed by mass spectrometry. Each helium profiles show the same general trends. Helium concentrations measured in the borehole C COx pore water are about 2 to 3 times lower than those observed for the other boreholes, and so comparable with previous measurements in the Underground Laboratory. These lower concentrations for borehole C could suggest differences in water average velocities in Dogger limestone, in comparison with the other ones. Calculations using a 1-D model were done; the results corroborate analytical measurements and confirm that helium diffusion profiles in the COx are controlled by Dogger helium concentrations that were put in the model. The vertical profile of dissolved helium concentration throughout the deep borehole suggest on the one hand that there is no deep crustal flux, and on the other hand that Trias is well isolated from the Lias and Dogger overlaying formations.The whole results obtained in this study provide a better understanding about diffusive transfer processes occurring in the COx and in the surrounding limestone aquifers
Clements, Philip Jameson. "Roll to Save vs. Prejudice: The Phenomenology of Race in Dungeons & Dragons." Bowling Green State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1448050814.
Full textLiu, Yuting. "Tangram Race Mathematical Game: Combining Wearable Technology and Traditional Games for Enhancing Mathematics Learning." Digital WPI, 2014. https://digitalcommons.wpi.edu/etd-theses/1102.
Full textShao, Kejun. "Kinetic Study of the Reactions of Chlorine Atoms with Fluoromethane and Fluoromethane-d3 in the Gas Phase." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc1011808/.
Full textDoshi, Viral V. "MEASUREMENT OF ALGAL GROWTH RATE BETWEEN HARVESTS IN AN ARTIFICIALLY LIT PHOTOBIOREACTOR UNDER FLUE GAS CONDITIONS." Ohio University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1164057276.
Full text