Dissertations / Theses on the topic 'Trapping'
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1
Callan, M. A. "Trapping modes." Thesis, University of Bristol, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303739.
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Raab, Eric Lowell. "Trapping sodium with light." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/118103.
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Edmunds, P. D. "Trapping ultracold argon atoms." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1462806/.
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This thesis describes the dipole trapping of both metastable and ground state argon atoms. Metastable argon atoms are first Doppler-cooled down to ∼80 μK in a magneto- optical trap (MOT) on the 4s[3/2]2 to 4p[5/2]3 transitions. These were loaded into dipole traps formed both within the focus of a high-power CO2 laser beam and within an optical build-up cavity. The optical cavity’s well depth could be rapidly modulated: allowing efficient loading of the trap, characterisation of trapped atom temperature, and reduction of intensity noise. Collisional properties of the trapped metastable atoms were studied within the cavity and the Penning and associative losses from the trap calculated. Ground state noble gas atoms were also trapped for the first time. This was achieved by optically quenching metastable atoms to the ground state and then trapping the atoms in the cavity field. Although the ground state atoms could not be directly probed, we detected them by observing the additional collisional loss from co-trapped metastable argon atoms. This trap loss was used to determine an ultra-cold elastic cross section between the ground and metastable states. Using a type of parametric loss spectroscopy we also determined the polarisability of metastable argon at the trapping wavelength of 1064 nm.
4
Churchill, Layne Russell. "Trapping triply ionized thorium isotopes." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37161.
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Cold trapped ions have many applications in quantum information science and precision metrology. In this thesis, we present progress toward two objectives involving ions confined to linear RF traps: the strong coupling of Ba+ ions with a high finesse optical cavity, and the observation of an optical nuclear transition in 229Th3+. In pursuit of the first objective, a novel high-temperture vapor cell for the spectroscopy of neutral barium was constructed. Using this vapor cell, a new technique for isotope-selective photoionization loading of Ba+ in an ion trap was developed. In pursuit of the second objective, techniques ultimately to be used in creating, trapping, and observing 229Th3+ are studied using 232Th3+. Ion traps are loaded with 232Th3+ via laser ablation of thorium targets. 232Th3+ is detected optically using laser-induced fluorescence and electronically using a channel electron multiplier. A technique for creating ablation targets from trace quantities of thorium nitrate is presented. The primary loss mechanisms of Th3+, charge exchange and chemical reactions, are studied.
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Shave, Evan Eric. "pH-biased isoelectric trapping separations." Diss., Texas A&M University, 2005. http://hdl.handle.net/1969.1/4184.
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The classical isoelectric trapping (IET) technique, using the multicompartment
electrolyzer (MCE), has been one of the most successful electrophoretic techniques in
preparative-scale protein separations. IET is capable of achieving high resolution
discrimination of proteins, by isolating proteins in between buffering membranes, in
their isoelectric state. However, due to the inherent nature of the IET process, IET has
suffered several shortcomings which have limited its applicability. During a classical
IET separation, a protein gets closer and closer to its pI value, thus the charge of the
protein gets closer and closer to zero. This increases the likelihood of protein
precipitation and decreases the electrophoretic velocity of the protein, thus making the
separation very long. Furthermore, the problems are aggravated by the fact that the
instrumentation currently used for IET is not designed to maximize the efficiency of
electrophoretic separations.
To address these problems, a new approach to IET has been developed, pH-biased IET.
By controlling the solution pH throughout the separation, such that it is not the same as
the proteinâÂÂs pI values, the problems of reduced solubility and low electrophoretic
migration velocity are alleviated. The pH control comes from a novel use of isoelectric buffers (also called auxiliary isoelectric agents or pH-biasers). The isoelectric buffers are
added to the sample solution during IET and are chosen so that they maintain the pH at a
value that is different from the pI value of the proteins of interest. Two new pieces of
IET instrumentation have been developed, resulting in major improvements in protein
separation rates and energy efficiency. A variety of separations, of both small molecules
and proteins, have been successfully performed using the pH-biased IET principle
together with the new instrumentation.
6
Warburton, Paul Anthony. "Quasiparticle trapping in superconducting heterostructures." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318419.
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Frohn, Matthew G. W. "Promoter trapping in Dictyostelium discoideum." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343041.
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Mellor, Christopher Daniel. "Optical trapping of colloidal particles." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419317.
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Butler, Eoin. "Antihydrogen formation, dynamics and trapping." Thesis, Swansea University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678341.
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Brodie, Graham. "Hybrid optical and acoustic trapping." Thesis, University of Dundee, 2014. https://discovery.dundee.ac.uk/en/studentTheses/8c6f10f1-7e43-4336-8e10-4d146ae87785.
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The need for non-contact micromanipulation methods is apparent for a number of different applications. Optical tweezers, a technique which uses highly focused laser beams to trap and move microscopic objects, has become an important tool for many applications owing to its incredible precision and dexterity. Optical trapping is, however, limited in several ways. It often struggles with particles larger than 10 micrometers, agglomerates and large numbers of particles. Complimentary technologies such as acoustic trapping, aim to overcome some of these limitations. This technique, also termed as Sonotweezers, uses ultrasonic fields to manipulate particles and can manipulate large particles with ease and manipulate large numbers of polydisperse particles and agglomerations, although they currently lack the dexterity of optical tweezers. Combining these two trapping modalities overcomes the some of the limitations of both of them and opens up a new range of useful applications. Three main types of hybrid optical and acoustic traps have been devised and are presented here. The first is an acoustic Bessel beam trap which is used to arrange a large number of polydisperse particles into concentric rings whereupon the smaller particles can then be further manipulated using a single beam optical tweezer. A rudimentary optical sorting system, which pushes particles in a flow laterally using an optical trap, has been combined with an acoustic levitator, which moves all particles away from the edges of the microfluidic channel reducing on sticking and other negative effects. A novel optically transparent ultrasonic device has been developed for easier integration into optical traps without the need for modication. This transparent trap has also been used in combination with a multibeam interference optical sorter to improve the separation between 5 and 10 micron particles.
11
Kim, Soo Y. "Radiation Trapping in Optical Molasses." Miami University / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=miami1057846181.
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Maruyama, Reina. "Optical trapping of ytterbium atoms /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/9778.
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Straub, Andreas. "Flux Trapping in Superconducting Pellets." PDXScholar, 1992. https://pdxscholar.library.pdx.edu/open_access_etds/4535.
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This research concerns the effects on samples of nominal composition Bil.8Pb0.2Sr2Ca2cu30y which were exposed to hot, dense argon in a ballistic compressor. The investigations were concentrated on two specimens which were exposed to hot, dense argon at about 1800 K (peak pressure 330 atm) and 1500 K (peak pressure 230 atm), respectively. Sample Bi #1 showed a completely melted surface structure after triple exposure in the ballistic compressor at 1800 K while the surface of sample Bi #7 was just partly melted after double exposure at 1500 K. Changes in flux trapping capability and qualitative Meissner effect were investigated in addition to the properties described by Duan, et al. ( 17, 18, 3 2] , who reported changes in critical temperature, crystal structure, surface morphology and composition after exposure of samples to hot, dense argon. After triple exposure in the ballistic compressor at a temperature of approximately 1800 K, sample Bi #1 showed an enhanced Meissner effect on the exposed side compared to the unexposed side of the pellet, while no difference in Meissner effect was found between the exposed and the unexposed side of sample Bi #7. EDS analysis showed that both samples are inhomogeneous in chemical surface composition. Oxygen loss due to exposure to hot, dense argon could not be demonstrated. X-ray analysis indicated that the melted surface layer of sample Bi # 1 after triple exposure to hot, dense argon contains smaller crystals than before exposure in the ballistic compressor. Tc measurements gave varying results which are explainable by the chemical inhomogeneity of the specimens. An increase in the amount of trapped flux due to exposure of the samples to hot, dense argon could not be demonstrated
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Bassindale, Philip George. "The development of ultrasonic acoustic trapping." Thesis, University of Bristol, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.720858.
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Martin, Jocelyn L. "Magnetic trapping and cooling in caesium." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361996.
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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.
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Hawes, A. C. "The intramolecular trapping of acyllithium ions." Thesis, Swansea University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637246.
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There are few useful synthetic methods of treating organolithium with carbon monoxide to form acyllithium ions. Those which do exist involve in the main the use of extremely low temperatures. This is due to the extreme reactivity of those ions. In this project a reaction is developed using organolithium compounds in which an electrophile is incorporated. Upon formation of the acyllithium compound by exposing the organolithium compound to carbon monoxide electrophillic attack occurs on the incorporated electrophile to give a hetrocyclic product. Chapter 1 is a survey of the field of the reactions of acyllithium ions. In Chapter 2 the compounds investigated were N-tert-butoxycarbonylaniline, in the hope that the N-tert-butoxycarbonylaniline group would act as an ortho directing group and 2-bromo-N-tert-butoxycarbonylaniline which could be readily lithiated in the ortho position by means of a bromine-lithium exchange. The acyllithium compound formed from those compounds would not undergo intramolecular trapping however. In Chapter 3 N,N-dimethyl-N'-(2-bromophenyl)urea and its derivatives were used to form the corresponding dilithium compounds which were treated with carbon monoxide to give the acyllithium ions which underwent rapid intramolecular trapping to give isatins as the product in fair yield. In forming substituted starting materials the appropriate 2-bromo-4-substituted aniline was treated with triphosgene to convert this to the corresponding phenylisocyanate, which, in turn could be converted to the urea starting material. Those were, in turn used to form the substituted isatins. Chapter 4 describes the extension of this reaction to a hetrocyclic system. The compounds used were 2 and 4-(pivaloylamino)pyridine and substituted derivatives of 2-(pivaloylamino)pyridine. The lithiation reaction gave good yields on trapping with simple electrophiles but lower yields from the reaction in which the aza-dioxindole products were obtained.
18
Townsend, Christopher G. "Laser cooling and trapping of atoms." Thesis, University of Oxford, 1995. http://ora.ox.ac.uk/objects/uuid:6a3d235b-22da-412b-b34b-e064322336d5.
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A detailed experimental and theoretical investigation of a magneto-optical trap for caesium atoms is presented. Particular emphasis has been placed on achieving high spatial number densities and low temperatures. Optimizing both of these together enables efficient evaporative cooling from a conservative trap, a procedure which has recently led to the first observations of Bose-Einstein condensation in a dilute atomic vapour. The behaviour of a magneto-optical trap is nominally determined by four independent parameters: the detuning and intensity of the light field, the magnetic field gradient and the number of trapped atoms. A model is presented which incorporates previous treatments into a single description of the trap that encompasses a wide range of its behaviour. This model was tested quantitatively by measuring the temperature of the cloud and its spatial distribution as a function of the four parameters. The maximum density was found to be limited both by the reabsorption of photons scattered within the cloud and by a reduction of the confining force at small light shifts. The nonlinear variation with position of the restoring force was found to be significant in limiting the number of atoms confined to a high density. A maximum density in phase space (defined as the number of atoms in a box with sides of dimension one thermal de Broglie wavelength) of (1.5 ± 0.5) x 10-5 was observed, with a spatial density of 1.5 x 1011 atoms per cm3. Cold collision losses from a caesium magneto-optical trap have been studied with the purpose of assessing their influence on spatial densities. In contrast to previous measurements of similar quantities, these measurements did not require the use of an ultra-low (< 10-10 Torr) background vapour pressure. The dependence of the cold collision loss coefficient β on the trapping intensity was measured to permit identification of the different cold collision processes. The largest loss rates observed were those due to hyperfine structure-changing collisions, with a coefficient β = (2±1) x 10-10cm3s-1. A study is presented of a modified magneto-optical trap in which a fraction of the population is shelved into a hyperfine level that does not interact with the trapping light. In this so-called "dark" magneto-optical trap, improved densities of nearly 1012cm-3 have been previously reported for sodium. The application of the technique to caesium is not straightforward due to the larger excited state hyperfine splittings. A simple theory for caesium is presented and its main predictions verified by measurements of density, number and temperature. A density of nearly 1012cm,-3 was indeed obtained but at a temperature substantially higher than in the conventional magneto-optical trap.
19
Gibson, Mandy. "Intramolecular trapping of aromatic #sigma#-radicals." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266706.
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Edmunds, A. J. F. "Stereochemical and trapping studies of biradicals." Thesis, University of Warwick, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378283.
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Schmidt, Julian [Verfasser], and Tobias [Akademischer Betreuer] Schätz. "Optical trapping of ion Coulomb crystals." Freiburg : Universität, 2018. http://d-nb.info/1166559432/34.
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O'Mahony, Donogh John Roger. "Rearrangement and trapping of organozinc carbenoids." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308938.
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Mackay, David Bain. "Specific carbohydrate radicals and spin trapping." Thesis, University of Aberdeen, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277363.
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γ-irradiation of solid sugars produces a large number of radicals, detection of which is possible by e.s.r. However, unambiguous interpretation of these e.s.r. signals is extremely difficult either by direct measurement or by spin trapping/hplc methods. The present study set out to prepare specific sugar spin adducts and to compare their e.s.r. spectra with those obtained by spin trapping radicals present in γ-irradiated solid sugars. In this way unambigous identification of the spin adducts may be achieved. Most specific carbohydrate radicals have previously been prepared using tri-alkyl tin radicals and protected halo-sugars in organic solution. To impart water solubility to the tin radicals, the preparation of hexa(3-pyridyl-1'-oxide)ditin was attempted and resulted in the synthesis of a new tetra(3-pyridyl)tin. Model halogeno compounds on reaction with the carbon dioxide radical anion CO2.-, gave radicals which were trapped with 2-methy-2-nitrosopropane (MNP)) and the adducts identified by e.s.r. Both carboxylic acids, and ketones with an adjacent halogen, underwent reductive elimination to form on spin trapping, the dehalogenated spin adduct. Where the halogen, X = C1,Br is adjacent to a primary or secondary alcohol, oxidation occurred before dehalogenation. However, where X = I, oxidation did not occur and the corresponding deioinated radical was obtained. Iodo sugars were synthesised and selectively deiodinated using CO2.- to give specific carbohydrate radicals that were trapped with MNP and the adducts identified by e.s.r. New b N-t-butyl carbohydrate nitrones were prepared by reaction of the corresponding aldehyde and N-t-butylhydroxylamine. Derivatives were prepared by [2+3] cycloaddition reactions with styrene and dimethylacetylene dicarboxylate. Using these nitrones as spin traps, several simple radicals were trapped to give the corresponding spin adduct. The e.s.r. spectra obtained from the hydroxyl radical derived spin adducts showed small aH coupling constants in contrast to those already published for similar adducts. This is explained in terms of hydrogen bonding which fixes the conformations of these spin adducts.
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Wei, Wenbin. "Promoter trapping in tobacco and Arabidopsis." Thesis, University of Leicester, 1996. http://hdl.handle.net/2381/35367.
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A promoter trapping system based on the promoter trap vector pDeltaGUSBin19 was studied for the identification and isolation of developmentally regulated plant genes. pDeltaGUSBin19 contained a promoterless gusA gene and a nos promoter-driven nptII gene. The previously unknown regions of pDeltaGUSBin19 were sequenced. A method of high frequency transformation of Arabidopsis thaliana by Agrobacterium-tumefaciens was developed. The T-DNA of pDeltaGUSBin19 was introduced into tobacco and Arabidopsis to generate a large number of transformed lines. The levels and patterns of gusA gene activation in diverse organs and cell types of transgenic plants were analysed. Line atvt1 exhibited GUS fusion activity in the tapetum and vascular tissues. It contained a single copy of the T-DNA and the gusA gene fusion was transcribed as a fusion transcript. Wild-type genomic and cDNA clones corresponding to the tagged gene were isolated using a molecular probe generated by IPCR of genomic sequence flanking the T-DNA. The native mRNA was approximately 4.4 kb. The foil length cDNA of this gene was cloned, sequenced and analysed. It encoded a putative nucleic acid helicase, designated HVT1 (Helicase in Vascular tissue and Tapetum). Of a predicted 1291 amino acid residues, HVT1 is homologous to the Drosophila MALELESS, human RNA helicase A and bovine nuclear DNA helicase proteins, and represents the first identified member of a new subgroup within the mle group of the DEAH protein family. Low stringency genomic Southern blot analysis indicates there exists another structurally related gene in Arabidopsis. The value of promoter trapping as a complement to other approaches of gene isolation and possible function of the HVT1 protein is discussed.
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Brown, David Ross S. B. Massachusetts Institute of Technology. "Trapping cold rubidium in a fiber." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40908.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2007.Includes bibliographical references (p. 79-80).
In this thesis, we demonstrate the novel technique of loading cold ⁸⁷Rb into a red-detuned optical dipole trap within a hollow core photonic fiber. This confines the atoms to 6 microns in two dimensions. We initially cooled the Rubidium in a magneto-optical trap. The great confinement of the Rubidium allows for increased optical depths per atom and therefore increased interaction rates with probing light.
by David Ross Brown.
S.B.
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Mohtar, Mohd Nazim. "Analysis and optimisation of electroosmotic trapping." Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582879.
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The phenomena of AC electroosmosis (ACEO) and dielectrophoresis (DEP) which are AC electrokinetics (ACEK) phenomenon but the earlier is always referred as AC electrohydrodynamic (AC ERD), have been used for many years to study, manipulate, trap, separate and collect particles of different scales and origins. The techniques have been adopted by builders of Microelectromechanical systems (MEMS) for Lab on a Chip (LaC) and Micro Total Analysis System (flTAS) for developing microfluidic devices. In this work, electrodes have been used to investigate these phenomena, to understand and optimise electroosmotic (EO) trapping. The effect of medium viscosity, medium density and temperature has been examined. It has been shown that medium viscosity is dominant over medium density as factor that affects EO trapping. It is also has ruled out centrifugal force as the dominant factor of EO trapping. Additionally, this work has investigated the effect of chamber height and electrode size on the efficiency of EO trapping.
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Soleimani, Nazila. "Light trapping in fluorescent solar collectors." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/348939/.
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A fluorescent solar collector (FSC) is an optoelectronic waveguide device that can concentrate both diffuse and direct sunlight onto a solar cell which is then converted to electricity. Fluorescent collectors offer the potential to reduce the cost of crystalline silicon (c-Si) solar cells, but so far their effectiveness has been demonstrated only theoretically. The major problems in the device obtaining high practical efficiency are photon transport losses and material instability. This aim of this research is to increase the fundamental understanding of photon transport losses in fluorescent collectors, and to explore the method in overcoming the losses in fluorescent solar collectors. This thesis presents the theoretical and experimental results obtained during the development and characterisation of fluorescent collectors, a thin film c-Si solar cell used to detect photons from the fluorescent solar collector. A method for preparing fluorescent collector plates was by spin-coating dye-doped PMMA (Polymethylmethacrylate) on glass slides (BK7 glass). An optical characterisation technique for determining reabsorption loss of the fluorescent collectors was developed and used to evaluate the performance of the fluorescent collector base on laser dyes. The validity of this approach was verified by comparing the results with theoretical solutions, derived using a model adapted from the Weber and Lambe, and the modified Weber and Lambe, theories. Different losses in the FSC are studied in this work and we investigate the effect of surface scattering in a realistic FSC. To characterise the photon transport inside the collector, we monitor the angular distribution of a collimated light beam, which enters the collector from the edge, after propagation and total internal reflection. We find that the surface scattering process is described well by Fraunhofer diffraction at surface inhomogeneities of a size, roughly 11 μm. The major losses in FSC are found to be caused by the surface roughness, which increases the probability of the escape cone losses in FSC from the top surface. This loss can be suppressed to less than 2% using an index matching planarisation layer. The influence of the bulk and surface scattering on the performance of the FSC are presented in this work, which were compared with the experiment and theory. The angular dependence of the edge fluorescence was studied in this work, and it showed the edge fluorescence decreases by increasing the detection angle, and the value of reabsorption also decreases by increasing the detection angle, up to 20°, before increasing again. It was shown, also, that that the quasi blackbody function agrees well with angular dependence of the edge fluorescence spectral, divided by the cos(detection angle) region where the absorption and fluorescence band of the dye overlap. Also, the modified Weber and Lambe theory for the angular dependence of the fluorescence agreed well with the experimental results.
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Piccio, Vincent J. D. "Generation and trapping of chiral enolates." Thesis, University of Bath, 2003. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289472.
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Nyström, Ville. "Sodium trapping in aluminium current collectors." Thesis, Uppsala universitet, Strukturkemi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-390889.
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The aim of this master thesis was to establish if sodium is trapped in aluminium current collectors, which in turn could affect the capacity fade in sodium-ion battery systems. In the case of lithium-ion batteries, previous studies have shown that a trapping mechanism, where lithium diffuses through the active material and current collectors, can explain the capacity fade observed for several systems. However, no such reports have been published in the sodium case, motivating this pioneering investigation. Contact samples of sodium and aluminium current collector material confirmed the uptake of sodium as shown by ICP-AES analyses. The uptake of sodium in the aluminium was equivalent to a charge of 0.4 µAh after 70 days of contact at 55°C. The main characterisation method was galvanostatic plating and stripping of sodium on aluminium in a pouch-cell configuration. When using a bare aluminium working electrode with a metallic sodium counter electrode in a 1 M NaPF6/diglyme electrolyte, the galvanostatic cycling showed coulombic efficiency instabilities. It was concluded that a more stable, high efficient plating-stripping would be needed to quantify the effects of sodium trapping with the employed electrochemical methods. Coulombic efficiency values that exceeded 100 % were attributed to the oxidation of disconnected (detached) sodium from previous plating cycles. On consecutive cycles some of the disconnected sodium got reconnected, resulting in coulombic efficiency values well over 100 %.
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Cabello, Hernández Pablo Jesús. "Single nanoparticle devices: Trapping and characterizaton." Tesis, Universidad de Chile, 2017. http://repositorio.uchile.cl/handle/2250/150605.
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Magíster en Ciencias, Mención FísicaLa fabricación y posicionamiento de nanopartículas de tamaño y composición ajustable resulta interesante debido a las propiedades que surgen producto del confinamiento en bajas dimensiones. Para acceder a ellas es necesario reemplazar los dispositivos electrónicos macroscópicos típicos por equivalentes nanométricos. En este campo, uno de los mayores retos es elaborar un esquema de medición que permita estudiar el transporte de cargas a través de una nanopartícula individual. Con tal de contactar las nanopartículas a los electrodos en este nuevo esquema, es necesario conocer tanto las propiedades de ambos como sus interacciones. Dado el tamaño reducido de las nanopartículas, resulta fundamental el poder fabricar electrodos nano-espaciados. En esta tesis se realizaron caracterizaciones eléctricas de dos tipos de nanopartículas: análogas al azul Prusiano (PBA por su sigla en ingles) y a base de hierro. Dichas nanopartículas fueron depositadas sobre muestras de electrodos nano-espaciados fabricados mediante la técnica de enmascaramiento con óxido de cromo. Se concluyó que estos dispositivos son una plataforma confiable para un amplio rango de temperaturas ($4$-$300$ K). Más aún, se pudo establecer que son compatibles tanto con técnicas actualmente disponibles como drop-casting, como con nuevas técnicas como la deposición directa de clústeres generados por pulverización catódica con magnetrón. La caracterización eléctrica de las nanopartículas de \ce{CoFe} PBA depositadas por \textit{drop-casting}, permitió demostrar que es posible atraparlas y estudiar sus curvas corriente-voltaje usando los dispositivos fabricados. Sin embargo, los datos obtenidos a bajas temperaturas no permitieron esclarecer el mecanismo involucrado en el transporte eléctrico. En este sentido es importante mencionar que se observaron dos comportamientos: Un primer grupo de dispositivos que no mostró evidencia de ser afectado por el láser ($640$ nm) y que presentó un \textit{Coulomb gap}, sugiriendo transporte individual de electrones; y un segundo grupo en el que si se evidenció un efecto tras la irradiación, que no se presenta \textit{Coulomb gap}, y cuya dependencia en temperatura de la resistencia se desvió fuertemente de la ecuación de Arrhenius ($\log(R) \propto T^{-1}$). En el caso de las nanopartículas a base de hierro, se consideró un nuevo esquema de fabricación y depósito de éstas, utilizando pulverización catódica. Mediciones a temperatura ambiente indicaron que las nanopartículas habían sido atrapadas entre los electrodos tras depositarlas. Las mediciones a baja temperatura mostraron una disminución en la resistencia medida y la aparición de un \textit{Coulomb gap}, lo que sugiere transporte individual de electrones. Usando teoría ortodoxa, y la aproximación de condensador de placas paralelas, fue posible estimar que el tamaño del punto de contacto entre la nanopartícula y los electrodos estaba en el rango de $1$ a $2$ nm, lo cual tiene sentido dado el tamaño de las primeras.
Este trabajo ha sido financiado a través de los Proyectos Fondecyt 1140770 y DAFNEOX
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Bellisardi, Federico. "Studio del trapping adiabatico per mappe stocastiche." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9573/.
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In questa tesi vengono trattati argomenti relativi alla dinamica dei fasci di particelle: in particolare si è preso in considerazione il moto betatronico di una particella carica all'interno di un acceleratore circolare. Vengono quindi discussi alcuni aspetti della dinamica trasversa introducendo il formalismo Hamiltoniano e discutendo il modello presentato da Hénon per il caso bidimensionale.
Viene poi introdotta la teoria adiabatica al fine di studiare gli effetti intrappolamento di un ensemble di particelle.
Infine vengono presentate alcune simulazioni che permettono di poter osservare come il rumore rappresenti un fattore di rilevante importanza nello studio di tali fenomeni.
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Antal, Peter. "Trapping problems for the simple random walk /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10759.
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Lee, Woei Ming. "Optical trapping : optical interferometric metrology and nanophotonics." Thesis, St Andrews, 2010. http://hdl.handle.net/10023/882.
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Dare, Kahan McAffer. "Tools for trapping and detecting ultracold gases." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57889.
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We construct a vertical imaging system designed to image along the quantization axis of the experiment. We demonstrate that it has a resolution on the order of 1-2μm which is on par with previous characterizations of the constituent components. We find that the inclusion of the vertical imaging system has a detrimental effect on the atom loading performance of the MOT. We show that this decrease is by approximately a factor of 2 down to 6.5×10⁶ atoms per second and 8.1×10⁷ atoms respectively. We subsequently detail the design of a novel lattice apparatus capable of tuning the lattice spacing by many orders of magnitude on the timescale of a typical experimental cycle. A proof-of-principle for this so-called dilating lattice is realized and the mechanism for variable lattice spacing is shown to work. Lastly, we cover our efforts towards measuring the effect of Feshbach resonances on collisional decoherence rates in ⁶Li. To this end, we show that the Rabi frequency we can create given our current tools is approximately 100Hz. A unknown strong mechanism for decoherence obstructs our experimental signature and a brief discussion of our attempts to discover its origin is presented.Science, Faculty of
Physics and Astronomy, Department of
Graduate
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Ganic, Djenan, and dga@rovsing dk. "Far-field and near-field optical trapping." Swinburne University of Technology. Centre for Micro-Photonics, 2005. http://adt.lib.swin.edu.au./public/adt-VSWT20051130.135436.
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Optical trapping techniques have become an important and irreplaceable tool in many research disciplines for reaching non-invasively into the microscopic world and to manipulate, cut, assemble and transform micro-objects with nanometer precision and sub-micrometer resolution. Further advances in optical trapping techniques promise to bridge the gap and bring together the macroscopic world and experimental techniques and applications of Microsystems in areas of physics, chemistry and biology.
In order to understand the optical trapping process and to improve and tailor experimental techniques and applications in a variety of scientific disciplines, an accurate knowledge of trapping forces exerted on particles and their dependency on environmental and morphological factors is of crucial importance. Furthermore, the recent trend in novel laser trapping experiments sees the use of complex laser beams in trapping arrangements for achieving more controllable laser trapping techniques. Focusing of such beams with a high numerical aperture (NA) objective required for efficient trapping leads to a complicated amplitude, phase and polarisation distributions of an electromagnetic field in the focal region. Current optical trapping models based on ray optics theory and the Gaussian beam approximation are inadequate to deal with such a focal complexity.
Novel applications of the laser trapping such as the particle-trapped scanning near field optical microscopy (SNOM) and optical-trap nanometry techniques are currently investigated largely in the experimental sense or with approximated theoretical models. These applications are implemented using the efficient laser trapping with high NA and evanescent wave illumination of the sample for high resolution sensing. The proper study of these novel laser trapping applications and the potential benefits of implementation of these applications with complex laser beams requires an exact physical model for the laser trapping process and a nanometric sensing model for detection of evanescent wave scattering.
This thesis is concerned with comprehensive and rigorous modelling and characterisation of the trapping process of spherical dielectric particles implemented using far-field and near-field optical trapping modalities. Two types of incident illuminations are considered, the plane wave illumination and the doughnut beam illumination of various topological charges. The doughnut beams represent one class of complex laser beams. However, our optical trapping model presented in this thesis is in no way restricted to this type of incident illumination, but is equally applicable to other types of complex laser beam illuminations. Furthermore, the thesis is concerned
with development of a physical model for nanometric sensing, which is of great importance for optical trapping systems that utilise evanescent field illumination for achieving high resolution position monitoring and imaging.
The nanometric sensing model, describing the conversion of evanescent photons into propagating photons, is realised using an analytical approach to evanescent wave scattering by a microscopic particle. The effects of an interface at which the evanescent wave is generated are included by considering the scattered
field reflection from the interface. Collection and imaging of the resultant scattered field by a high numerical aperture objective is described using vectorial diffraction theory. Using our sensing model, we have investigated the dependence of the scattering on the particle size and refractive index, the effects of the interface on the scattering cross-section, morphology dependent resonance effects associated with the scattering process, and the effects of the incident angle of a laser beam undergoing total internal reflection to generate an evanescent field. Furthermore, we have studied the detectability of the scattered signal using a wide area detector and a pinhole detector. A good agreement between our experimental measurements of the focal intensity distribution in the back focal region of the collecting objective and the theoretical predictions confirm the validity of our approach.
The optical trapping model is implemented using a rigorous vectorial diffraction theory for characterisation of the electromagnetic field distribution in the focal region of a high NA objective. It is an exact model capable of considering arbitrary amplitude, phase and polarisation of the incident laser beam as well as apodisation functions of the focusing objective. The interaction of a particle with the complex focused field is described by an extension of the classical plane wave Lorentz-Mie theory with the expansion of the incident field requiring numerical integration of finite surface integrals only. The net force exerted on the particle is then determined using the Maxwell stress tensor approach. Using the optical trapping model one can
consider the laser trapping process in the far-field of the focusing objective, also known as the far-field trapping, and the laser trapping achieved by focused evanescent field, i.e. near-field optical trapping.
Investigations of far-field laser trapping show that spherical aberration plays a significant role in the trapping process if a refractive index mismatch exists between the objective immersion and particle suspension media. An optical trap efficiency is severely degraded under the presence of spherical aberration. However, our study shows that the spherical aberration effect can be successfully dealt with using our optical trapping model. Theoretical investigations of the trapping process achieved using an obstructed laser beam indicate that the transverse trapping efficiency decreases rapidly with increasing size of the obstruction, unlike the trend predicted using a ray optics model. These theoretical investigations are in a good agreement with our experimentally observed results.
Far-field optical trapping with complex doughnut laser beams leads to reduced lifting force for small dielectric particles, compared with plane wave illumination, while for large particles it is relatively unchanged. A slight advantage of using a doughnut laser beam over plane wave illumination for far-field trapping of large dielectric particles manifests in a higher forward axial trapping efficiency, which increases for increasing doughnut beam topological charge. It is indicated that the maximal transverse trapping efficiency decreases for reducing particle size and that the rate of decrease is higher for doughnut beam illumination, compared with plane wave illumination, which has been confirmed by experimental measurements.
A near-field trapping modality is investigated by considering a central obstruction placed before the focusing objective so that the obstruction size corresponds to the minimum convergence angle larger than the critical angle. This implies that the portion of the incident wave that is passed through the high numerical aperture objective satisfies the total internal reflection condition at the surface of the coverslip, so that only a focused evanescent field is present in the particle suspension medium. Interaction of this focused near-field with a dielectric micro-particle is described and investigated using our optical trapping model with a central obstruction. Our investigation shows that the maximal backward axial trapping efficiency or the lifting
force is comparable to that achieved by the far-field trapping under similar conditions for either plane wave illumination or complex doughnut beam illumination. The dependence of the maximal axial trapping efficiency on the particle size is nearly linear for near-field trapping with focused evanescent wave illumination in the Mie size regime, unlike that achieved using the far-field trapping technique.
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Ganic, Djenan. "Far-field and near-field optical trapping." Australasian Digital Thesis Program, 2005. http://adt.lib.swin.edu.au/public/adt-VSWT20051130.135436.
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Thesis (PhD) - Swinburne University of Technology, Faculty of Engineering and Industrial Sciences, Centre for Micro-Photonics, 2005.A thesis submitted for the degree of Doctor of Philosophy, Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, 2005. Typescript. Includes bibliographical references (p. 164-177). Also available on cd-rom.
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Merry, Stephen Alan Paul. "Exciton transfer and trapping in photosystem II." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286500.
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Wu, J. "Materials for electron trapping optical memory (ETOMS)." Thesis, Coventry University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289102.
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Wilkins, Julie A. "Retroviral vector mediated gene trapping in mice." Thesis, Cardiff University, 2004. http://orca.cf.ac.uk/55911/.
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There is a great wealth of sequence information available nowadays, but this is accompanied by a serious lack of functional information. Functional genomics is an area that needs to be developed and one method being utilised is gene trapping. In this project a gene trapping approach was employed to achieve insertional mutagenesis in vitro in embryonic stem (ES) cells. These early embryo derived cell lines can be manipulated in vitro and then returned to the embryo where they participate in the normal development of a chimeric mouse. There are two types of gene trapping retroviral vectors being investigated, one is a shuttle vector which contains plasmid backbone between the long terminal repeats (LTRs) allowing the rescue of any trapped gene. The other is a splice acceptor (SA) vector, which has a SA in front of a promoterless P-geo gene. The provirus integrates into the genome of the ES cells and the trapped gene is tagged with the p-geo reporter gene. This enables trapped clones to be selected with G418 and expression patterns to be visualised by staining for p-galactosidase activity. Generation of a fused RNA transcript between the trapped gene and vector sequences facilitates cloning of the trapped gene. Using the P-geo sequence of the integrated vector, 3' RACE PCR was used to amplify a segment of the trapped gene and subsequently obtain sequence data. Two retroviral vectors of each type mentioned are examined in this project for their insertional mutagenesis ability in vitro in ES cells and subsequent analysis. Neither of the shuttle retroviral vectors gave any reproducible results. A comparison was made between the SA retroviral vectors, one containing an internal ribosome entry site (IRES), the other not. These vectors gave rise to resistant ES cell clones and subsequent 3' RACE PCR sequence data.
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Ghita, M. "Hydrogen diffusion and trapping in crystalline silicon." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517282.
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Brandt, Lukas. "Trapping of rubidium atoms using optical tweezers." Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558210.
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This thesis describes the realisation of a novel dipole force trapping method for cold neutral atoms, the optical tweezers. They are formed by imaging a spatial light modulator onto a mirror surface, by an aspherical lens. The spatial light modulator, a digital mirror device, consists of an array 1024 by 768 of micro-mirrors, which can individually be switched between the on and off position with a full frame refresh rate of 4 kHz and hence can create arbitrary light patterns in real time. Atoms are trapped through the dipole force in them. The optical tweezers have a potential depth on the order of 1 mK. A magneto-optical surface-trap cools and traps Rubidium atoms close to the mirror surface. Unlike a normal magneto-optical trap, which traps atoms in free space, this trap incorporates a mirror, above which the atoms are trapped and then loaded into the optical tweezers. I will show that we managed to load atoms into the dipole traps with a variety of different potential landscapes and observe them with a highly sensitive CCD-camera through fluorescence imaging. . . Furthermore I study a scheme to use a high powered, but spatial multimode diode laser for atom trapping. An optical diffuser smoothes out the otherwise poor quality profile, to make the high power diode laser applicable for optical tweezers.
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Pan, Yu. "Optical Trapping Force on a Plasmonic Substrate." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99560.
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Optical trapping is currently widely applied in the field of biotechnology, in which one critical issue is to manipulate cells in the micron-size scale without hurting or damaging them. The plasmonics-assisted optical trapping method is considered to be very promising for achieving more precise trapping of small particles compared to the conventional optical trapping method. In this project, the optical force exerted by an optical beam on a dielectric bead trapped on a substrate proliferated with nanometric gold-pillar pairs is numerically simulated in COMSOL Multiphysics environment. The numerical results show a clearly enhanced trapping capability, which is quantitatively manifested by a ten times higher trapping stiffness as compared to the scenario without the plasmonic-pillar pairs. The simulation results therefore prove that, given the same incident light condition, an appropriately designed nanometric plasmonic substrate can achieve a significantly higher trapping precision albeit Brownian motion; hence less heating damage will be induced in the trapping process, which can be vital for manipulating living cells in biotechnology.
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Saxton, Carl Graham. "Microporous adsorbents for trapping of gaseous pollutants." Thesis, University of Aberdeen, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446326.
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Adsorption studies (xenon and iodine) in microporous materials have been carried out on various materials such as zeolites (FAU, MFI, SAV and CHA) and metal-organic frameworks (MOF-5, HKUST-1 and JUC-32). The as-synthesised and commercial zeolites containing Na+, Li+ or K+ cations and then subsequently ion-exchanged for other extra framework cations. The xenon adsorption in zeolites was interpreted using isosteric heats of adsorption (CHA) and also 129Xe NMR (FAU). CHA type zeolites show a high affinity and capacity for xenon at low xenon pressures <10kPa. This affinity changes depending upon the extra framework cation present due to the positioning and size of the cation. The electric field gradient was a primary factor in the xenon adsorption since a neutral framework (ALPO-CHA) was found to have a lower affinity for xenon but having the same framework type. This was further highlighted by the introduction of Si into the framework and a comparison was made between the three structures CHA, ALPO-CHA and SAPO-34 with the latter being a silicon substituted aluminophosphate carrying a slightly negatively charged framework. Another framework studied was that of STA-7 (SAV) and it was found that varying the silicon within the framework had an effect upon the xenon adsorption. Xenon interaction with the MOFs was minimal when compared to the zeolites. MOF materials adsorbed more iodine per gram of material than any of the zeolites studied. In some materials, two different species of iodine exist. These species, I2 (isolated) and (I2)n (wires) have different Raman frequencies and the (I2)n species have been observed in MOFs for the first time.
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Williams, Hannah Jane. "Producing, trapping and controlling ultracold CaF molecules." Thesis, Imperial College London, 2018. http://hdl.handle.net/10044/1/62635.
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From studies of fundamental physics to quantum technologies the production of ultracold molecules will have a huge impact across a range of applications. For many years laser cooling, which became an invaluable tool in cold atomic physics, was deemed to be too impractical for application to molecules. Nevertheless, laser cooling has now been demonstrated for a few molecular species. Using a frequency-chirped laser slowing technique, the velocity distribution of a pulse of CaF molecules is compressed and slowed from 180 m/s to about 10 m/s. These slow molecules are then captured in a magneto-optical trap. I present measurements that show how the number of molecules, the photon scattering rate, the oscillation frequency, damping constant, temperature, cloud size and lifetime depend on the key parameters of the magneto-optical trap, especially the intensity and detuning of the main cooling laser. The trap contains up to 2*10^4 molecules, the maximum photon scattering rate is 2.5*10^6 s-1 per molecule, the maximum oscillation frequency is 100 Hz, the maximum damping constant is 500 s^-1, and the minimum rms radius of the trapped cloud is 1.5 mm. A minimum temperature of 730 microkelvin is obtained by ramping down the laser intensity to lower values. To reach lower temperatures, the cloud is loaded into a blue-detuned optical molasses, which cools the molecules to 55 microkelvin, well below the Doppler-limiting temperature. I characterise the cooling process and suggest the sub-Doppler mechanisms responsible. These ultracold molecules are the optically pumped into a single quantum state, and coherently transferred between selected hyperfine components of the ground and first-excited rotational states. Finally, the ultracold, state-selected molecules are loaded into a magnetic trap that has a lifetime of about 1 s.
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Haque, Nafis Ul. "Disorder trapping in rapidly solidified intermetallic compounds." Thesis, University of Leeds, 2018. http://etheses.whiterose.ac.uk/21646/.
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The congruently melting, single phase, intermetallic compounds β-Ni3Ge and ε-Ni5Ge3 were produced by arc melt. Each was subject to rapid solidification via drop-tube processing. Each compound remained fully single phase β-Ni3Ge/ ε-Ni5Ge3, irrespective of the imposed cooling rate. In the investigation of β-Ni3Ge compound, droplets spanning the size range ≥ 850 to ≤ 38 μm diameter particles, with corresponding cooling rates of ≤ 700 to > 54500 K s-1, were subject to microstructural investigation using SEM. Six dominant solidification morphologies were identified with increasing cooling rate, namely; (i) spherulites, (ii) mixed spherulites and dendrites, (iii) dendrites - orthogonal, (iv) dendrites - non-orthogonal, (v) recrystallised, and (vi) dendritic seaweed, are observed imbedded within a featureless matrix. Selected area diffraction (SAD) in the TEM analysis confirmed that it is only the spherulite microstructure that is partially ordered amongst the above listed microstructures, which are disordered. However, SAD analysis indicated that the featureless background material of all above microstructures is chemically ordered. While, in the examination of ε-Ni5Ge3 compound, four dominant solidification morphologies were observed, namely; (i) Partial plate and lath, (ii) plate and lath microstructure (iii) isolated hexagonal crystallites, and (iv) single crystal imbedded within a featureless matrix. SAD analysis in the TEM reveals that the partial plate and laths and plate and laths are partial ordered variant of έ-Ni5Ge3 and ε-Ni5Ge3 respectively, whilst the featureless matrix of both microstructures are the ordered variant of the same compound. However, isolated hexagonal crystallites are a disordered variant of ε-Ni5Ge3, although featureless matrix are the ordered variant of the same compound. SAD analysis in the TEM also indicated that, at the highest cooling rates, single crystal structure along with featureless matrix is the completely disordered variant of the same compound. Thermal analysis and in situ heating in the TEM indicate a reversible solid-state order-disorder transformation between 470 – 485 °C. The micro-Vickers hardness results confirmed that the ε-Ni5Ge3 (1021 Hv0.01) is significantly harder than the β-Ni3Ge (526 Hv0.01) compound.
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Harris, Thomas Miller. "Hydrogen diffusion and trapping in electrodeposited nickel." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/69707.
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Joffe, Michael Arnold. "Trapping and cooling atoms at high densities." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12229.
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Macdonald, Iain. "Charge trapping in nano-structured semiconducting oxides." Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=201922.
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This thesis explores the low temperature dynamics of photo-generated charges in titanium dioxide; with particular reference to the rutile polymorph. The phenomenon of charge trapping in anatase has been heavily investigated using electron paramagnetic resonance (EPR) spectroscopy, whereas the rutile polymorph has been given very little attention. An understanding of charge trapping dynamics in semiconductors, such as titanium dioxide, is of key importance to advancing technologies such as photocatalysis. The research contained in this thesis examines charge trapping in a number of rutile systems, nano- and micro-structured, and compares these finding with those of the anatase polymorph. For contrast, a similar EPR study was carried out on a hematite; an iron oxide semiconductor. The data highlights some interesting differences between the rutile and anatase polymorphs. Firstly, the trapped electrons in rutile are particularly sensitive to being re-excited to the conduction band by the further absorption of photons; as is not the case in anatase. This phenomenon has been termed in this work as a dynamic equilibrium between trap site and conduction band. Secondly, the observation of paramagnetic holes is very difficult in rutile systems, leading to the hypothesis of hydroxyl radical dimerisation; producing hydrogen peroxide of the surface. This hypothesis was formed following an extensive study of the effects of surface hydration. Most importantly, a number of distinctly different trapped electron species were observed in the rutile samples. The two main trapped electron species have been assigned to; i) an electron residing on a surface titanium ion associated with a hydroxyl group and ii) a sub-surface titanium ion residing in either a lattice or an interstitial site. Finally, the study conducted on Hematite at low temperature, shows evidence for a transition from ferromagnetism to superparamagnetism during broadband irradiation. An attempt to rationalise this observation is given within.
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Grimshire, Michael J. "Studies on intramolecular trapping of N-nitrenes." Thesis, University of Leicester, 1986. http://hdl.handle.net/2381/33708.
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The research described in this Thesis is an investigation of the intramolecular trapping of N-nitrenes by alkenes and alkynes. In the former case, the objective was to try to obtain a description of the transition state geometry for concerted addition of nitrenes to double bonds. This was attempted by a study of intramolecular nitrene additions since in the latter, some control over the approach geometry of the interacting components can be exercised by design of the molecular framework. From the effect of changes in this framework upon the characteristics of the cycloaddition, and in particular upon its concertedness, an ideal configuration for the participating atoms (i.e. transition state geometry) was definable. 2H-azirines are obtained in greatly improved yields in the intramolecular trapping of N-nitrenes by comparison with the analogous inter- molecular trapping. Analysis of the n.m.r. spectra of these azirines together with the X-ray crystal structure of one of them reveals that a preference for near-coplanarity of three of the bonds at the spiro-centre results in conformational anchoring of the five-membered ring. (Examination of all the azirine ring containing structures in the Cambridge crystallographic data file shows that all of these also show the same near-coplanarity of azirine C-C bond and substituent bonds at the spiro-centre). Attempts to trap a presumed 1H-azirine intermediate were unsuccessful. This is probably the result not only of their anti-aromatic character but also that migration of the N-N bond in the 1H-azirine delivers the 2H- azirines, in the cases studied, directly in their most stable conformations.
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Kaushik, Aisha. "Trapping, transport and polarisation of ultracold lithium." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/24908.
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The aim of our experiment is to explore two methods of creating an ultracold dipolar gas which can subsequently be used to simulate quantum phenomena. The first method is to sympathetically cool polar molecules. In this case, the molecules are overlapped with ultracold lithium atoms, thus allowing the two clouds to thermalise through elastic collisions. The second method is to electrically polarise ultracold lithium atoms using an electric field of approximately 1MV/cm. This involves placing the atoms between two high voltage electrodes. This thesis describes and characterises the setup used to produce, trap and transport a cloud of lithium-7 atoms. The setup consists of a lithium oven, Zeeman slower, magneto-optical trap (MOT) and magnetic trap. Up to 2.3x10^8 atoms are loaded into the MOT with an initial temperature of 1.3 mK. By implementing a compressed MOT phase the temperature is reduced to 0.75 mK. Before transport, 23% of the MOT atoms are transferred into the magnetic trap, which has a lifetime of 1.53±0.01 s in the MOT chamber. Using a motorised translation stage to move the magnetic trapping coils, atomic transport over a distance of 44 cm from the MOT chamber to the science chamber has been demonstrated. The transport efficiency is 41%. In the science chamber the lifetime of the magnetic trap has been measured as 18.5±0.7 s. Experiments to optimise the absorption imaging system have also been carried out, highlighting the fact that a time and position dependent magnetic field is present after the trapping coils switch off. The feasibility of producing a 1MV/cm electric field has been investigated. By using indium tin oxide coated glass electrodes in an adjustable electrode mount, an electric field of approximately 0.2MV/cm has been generated. These electrodes were subsequently replaced with super-polished stainless steel electrodes which generated a field of 0.38MV/cm.