Dissertations / Theses: 'Crystal14'

1

Shopova, Denitsa. "Crystal chemistry of fullerene co-crystals." [S.l. : s.n.], 2005. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB12103660.

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Bridgland, Lydia Naomi. "Crystal engineering of porous steroidal organic crystals." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627972.

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Porous materials are highly valued for a wide variety of scientific and technological applications and organic molecular crystals offer an alternative to established inorganic materials. In this thesis, the porosity of tris-N-phenylureido steroidal crystals IS characterised and the versatility of the steroidal crystal system is demonstrated. Material properties can often be adjusted by mixing components in varying proportions to form alloys, but this phenomenon is rarely demonstrated for organic molecules. In organic crystals, molecules pack into an array which has symmetry and dimensions specific to the compound. Thus, in general, molecules cannot be substituted for molecules of a different compound. The studies presented here demonstrate that organic alloys are possible if the crystal structure possesses voids which are able to accommodate significant p0l1ions of the new molecules. A variety of multi-component steroidal crystals have been created with diverse and complex channel interiors. These have been characterised by optical microscopy, single X-ray crystallography, IH NMR and mass spectrometry. Finally, molecular machines which perform mechanical work on a molecular level are of great interest within the scientific community. The operational range of molecular motion is often too restricted to create macroscopic phenomena, but by confining the molecular machines to small spaces such as nanopores, molecular movement on the nanometre level can be sufficient to dominate the physical and chemical behaviour of guest molecules. In this thesis, the prospect of creating a new type of molecular machine assembly to propel molecules unidirectionally along crystal channels has been investigated. Crystal engineering has been used to design porous steroidal crystals with azobenzene moieties, capable of photoinduced isomerisation, protruding into the crystal channels. The resulting crystals have been analysed by optical microscopy and solid-state UV-vis spectroscopy, and the distribution of guest molecules within the crystals has been investigated by Raman and IR microspectroscopy and fluorescence microscopy.

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Bullard, Theresa Vivian. "Luminescence labeling and dynamics of growth active crystal surface structures /." Thesis, Connect to this title online; UW restricted, 2008. http://hdl.handle.net/1773/9680.

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4

Higgenbottom, Morris Scott. "Liquid crystal modulation of retroreflection : a low-power communication/location technology." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/16695.

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Ahmed, Sayima J. "Crystal engineering of pharmaceutical salts and co-crystals." Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515715.

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Richartz, Melanie. "Klassifikation von selbstdualen Dieudonnégittern in einem dreidimensionale polarisierten supersingulären Isokristall." Bonn : [s.n.], 1998. http://catalog.hathitrust.org/api/volumes/oclc/41464660.html.

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7

Wu, Haixia. "Anchoring Behavior of Chiral Liquid Crystal at Polymer Surface: In Polymer Dispersed Chiral Liquid Crystal Films." Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-04082004-154054/unrestricted/wu%5Fhaixia%5F200405%5Fmast.pdf.

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Thesis (M.S.)--Textile and Fiber Engineering, Georgia Institute of Technology, 2004.
Griffin, Anselm, Committee Member; Srinivasarao, Mohan, Committee Chair; Park, Jung O., Committee Member. Includes bibliographical references (leaves 101-105).

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Evans, Herbert Elgin 1962. "Preparation of high-purity aluminum bicrystals." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277076.

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The preparation of bicrystal specimens of high interfacial purity and accurately controlled mismatch of orientation between grains with a specific boundary orientation are critical for fundamental studies of the structure and properties of grain boundaries. A method was developed for routinely producing high-purity aluminum bicrystals of desired mismatch and boundary orientation. A strain annealing technique was used for making large single crystals. The orientation, structural perfection, and chemical purity of the seeds were characterized, then the seeds were joined by using an electron beam welder. The welder was designed and built as a major portion of this work.

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Legge, Coulton Heath. "Structural modifications in liquid crystals and liquid crystal polymers." Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306164.

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Pyzer-Knapp, Edward Oliver. "Exploring the crystal energy landscapes of porous molecular crystals." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648625.

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Liu, Zhijian. "Photo-aligned LC cell with weak anchoring energy and specific profiles : physics & applications /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ECED%202006%20LIU.

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Paturi, Naveen Kumar. "Analysis of photonic crystal defects for biosensing applications." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4861.

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Thesis (M.S.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains viii, 70 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 55-57).

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13

Reznikov, Dmytro. "Effect of surface alignment layer on electro-optical properties of ferroelectric liquid crystal displays." [Kent, Ohio] : Kent State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1227562895.

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Thesis (Ph.D.)--Kent State University, 2008.
Title from PDF t.p. (viewed Jan 5, 2010). Advisor: Philip J. Bos. Keywords: liquid crystal, smectic, display, ferroelectric. Includes bibliographical references (p. 190-194).

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Griffin, Alexandra. "Crystal synthesis : a study of ionic hydrogen-bonding in crystals." Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443673.

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Oliveira, José E. B. (José Edimar Barbosa). "Generalized anisotropic acoustooptic diffraction in uniaxial crystals." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72766.

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Levandovsky, Artem. "Structure and dynamics of interfaces in the epitaxial growth and erosion on (110) and (100) crystal surfaces." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3731.

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Thesis (Ph. D.)--West Virginia University, 2004.
Title from document title page. Document formatted into pages; contains vii, 129 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

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17

GIGNONE, ANDREA. "Ordered Mesoporous Silica for Drug Delivery in Topical Applications." Doctoral thesis, Politecnico di Torino, 2016. http://hdl.handle.net/11583/2652565.

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The aim of this PhD work was to develop and characterize all physicochemical aspects of this new CRT for CTZ and AKS using OMS until the introduction onto the market. The first part comprehends the characterization of different OMS synthesized and commercially available; the study of different incorporation techniques based on hydrophilicity/hydrophobicity of API; the characterization of the new impregnated OMS. Consequently, the work is oriented on the interaction details of API on silica surfaces. A closer look is given to the big questions of OMS-drug phenomena: mobility, solubility, bioavailability, etc. Therefore, all the scCO2 incorporation parameters have been studied, highlighting the differences between OMS and the spatial assembly of drug inside the mesoporous channels. Thus, the patented CRT has been developed for AKS describing all the main aspect of the innovative semisolid formulation. In-vitro and ex-vivo release test has been produced and characterized, revealing the functionality of the OMS reservoir effect. Finally, the same DDS have been developed for CTZ. Both the DDS have been compared with commercially available creams.

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Cosquer, Guirec Yann. "Liquid crystals with novel terminal chains as ferroelectric liquid crystal hosts." Thesis, University of Hull, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322457.

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Shattock, Tanise R. "Crystal engineering of co-crystals and their relevance to pharmaceutical forms." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002101.

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Kim, Sang Hwa. "Fast Switching Polymer Stabilized Liquid Crystal Devices: Morphological and Electro-Optical Properties." [Kent, Ohio] : Kent State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1101220722.

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Hu, Zhen. "Modeling photonic crystal devices by Dirichlet-to-Neumann maps /." access full-text access abstract and table of contents, 2009. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ma-b30082559f.pdf.

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Thesis (Ph.D.)--City University of Hong Kong, 2009.
"Submitted to Department of Mathematics in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves [85]-91)

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Xu, Peizhi. "Electrooptical modes of liquid crystal for shutter and display applications /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20XU.

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Yeung, Fion Sze Yan. "Variable liquid crystal pretilt angles by nanostructured surfaces and their applications /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?ECED%202007%20YEUNG.

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Brown, Stephen James. "The Czochrlaski growth and characterisation of single crystals of lead molybdate." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364392.

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Chen, Peng 1960. "Precipitation and Pattern Formation under Far-From-Equilibrium Conditions." Thesis, University of North Texas, 1995. https://digital.library.unt.edu/ark:/67531/metadc278650/.

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Precipitates of a series of alkaline earth metal (barium and strontium) carbonates, chromates, phosphates, and sulfates were formed at high supersaturation by diffusion through silica hydrogel, agarose hydrogel, and the freshly developed agarosesilica mixed gels. The reaction vessels could be a small test tube, a recently designed standard micro slide cassette and a enlarged supercassette. Homogeneous nucleation is thought to have taken place, and particle development led to the formation of an unusual category of materials, known as Induced Morphology Crystal Aggregates [IMCA], at high pH under far-from-equilibrium conditions. Standard procedures were developed in order to produce homogeneous gels. Particle development led to characteristic style of pattern formation, which I have called monster, spiral, and flake. Among these IMCA, barium carbonate, chromate, and sulfate were moderately easy to grow. Barium phosphate was very difficult to grow as IMCA due to formation of poorly crystalline spherulites. IMCA of strontium carbonate, chromate and sulfate could be developed at high basic pH in the presence of silicate. Strontium carbonate sheet morphology displays a unique property, double internal layer structure, which was identified by backscattering electron imaging (BEI). Selected electron diffraction (SAD) revealed a new crystal phase which was called "Dentonite". Precipitate particles were isolated using a non-destructive isolation technique. Optical microscopy was widely used to examine particles in situ and scanning electron microscopy and X-ray dispersive energy (EDX) spectroscopy were applied to particles ex situ, together with ESCA for surface analysis. Growth patterns were found to be strongly dependent on pH. Other related pattern formation processes were also investigated including normal and dendritic structures, spherulitic structures and periodic pattern formation. Some interpretations were proposed in terms of mechanism. Chemical additive effects were examined experimentally in the calcium phosphate system. The effect of external ionic strength was investigated, and it was found that a certain concentration of sodium chloride (0.2 M) approximately equals a fraction of pH unit (-0.2).

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Du, Tao. "Single cell gap transflective liquid crystal displays and the use of photoalignment technology /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20DU.

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Huang, Danding. "Ferroelectric liquid crystal display based on photo-aligned azo-dye layers /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202004%20HUANGD.

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Amombo, Noa Francoise Mystere. "Crystal engineering of selected phenolic acids." Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/734.

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Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Chemistry in the Faculty of Applied Science at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2014
Crystal engineering based upon acid: base compounds have been studied in this thesis. Selected phenolic acids such as: vanillic acid (VA), phenylacetic acid (PAA), 4-hydroxyphenylacetic acid (HPAA), 3-chloro-4-hydroxyphenylacetic acid (CHPAA), caffeic acid (CFA), p-coumaric acid (pCA), trans-ferulic acid (tFER), 2-phenylpropionic acid (PPA) and 2-phenylbutyric acid (PBA) were the main compounds investigated. These phenolic acids have formed co-crystals/co-crystal hydrates, salts/salt hydrates and hybrid salt-co-crystals with acridine (ACRI), caffeine (CAF), cinchonidine (CIND), isonicotinamide (INM), isonicotinic acid (INA), nicotinamide (NAM), quinidine (QUID), quinine (QUIN), theobromine (THBR), theophylline (THPH) and urea (U). The two racemic compounds 2-phenylpropionic acid (PPA) and 2-phenylbutyric acid (PBA) were used to study chiral discrimination leading to the understanding of separation enantiomers. Compounds were prepared in different solvents (alcohols, ketone and distilled water) to investigate the relationship between solvents used and the crystalline product obtained. (If there is any effect on the crystalline compound obtained by changing the solvent). The structures were elucidated using single crystal X-ray diffraction. Ground products of obtained compounds were characterized by powder X-ray diffraction (PXRD). Thermal analyses like thermogravimetry (TG), differential scanning calorimetry (DSC) and hot stage microscopy (HSM) were used for the determination of thermal character of the new compounds. IR was also performed to characterize the new compounds. Non-isothermal TG was utilised to obtain kinetic parameters for the water and the methanol release in (pCA−)(QUIN+)•pCA•MeOH•H2O. A selective experiment was done in which quinidine and quinine were used to compete between selected phenolic acids (PAA and HPAA). viii The comparison of the crystal structures determined showed that, changing the phenolic acid while using the same co-crystal former has a significant effect on the type of compounds obtained. The obtained crystal structures were either co-crystal/co-crystal hydrates, salts/salt hydrates or hybrid salt-co-crystals which formed network via means of supramolecular interactions.

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Kovačević, Tijana [Verfasser], Heiko [Akademischer Betreuer] Briesen, Heiko [Gutachter] Briesen, and Xue Zhong [Gutachter] Wang. "Crystal Shape Characterization: From Single Crystals to Crystal Aggregates / Tijana Kovačević ; Gutachter: Heiko Briesen, Xue Zhong Wang ; Betreuer: Heiko Briesen." München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/1155923421/34.

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Dong, Shaosheng. "Liquid Crystal Polymers And Dendritic Liquid Crystals: Synthesis, Morphology, Rheology And Binary Mixtures." online version, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1094584392.

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31

Neupane, Krishna Prasad. "Light Scattering Studies of Orientational Order in Liquid Crystalline Tetrapodes and Lyotropic Chromonic Liquid Crystals." Kent State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=kent1239811255.

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Burnham, Kikue Sugiyama. "Phototriggers for a liquid crystal-based optical switch." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/27900.

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Park, Jun Gwan. "Characteristic behavior of a side branch in a dendritic crystal growth." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1187198212.

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Li, Xihua. "Bi and multi stable ferroelectric liquid crystal displays /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20LI.

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Zhang, Zichen. "Phase-only nematic liquid crystal on silicon devices." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610052.

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Jacobs, Tia. "Self-assembly of new porous materials." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/3970.

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Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: The primary objective of the work was to prepare and investigate new porous materials using the principles of crystal engineering. Both organic and metal-organic systems were studied and the work can best be divided into two separate sections: 1. The crystal engineering of Dianin’s Compound, a well-known organic host. 2. The design and synthesis of a series of related porous coordination compounds consisting of discrete, dinuclear metallocycles. The first section discusses the synthetic modification of Dianin’s compound in order to engineer a new clathrate host with an altered aperture size. Although this study ultimately failed to isolate the host material in its porous guest-free form, the work led to the discovery of a chiral host framework that aligns guest molecules in a polar fashion, and consequently displays non-linear optical properties. These findings are unprecedented in the long history of crystal engineering of Dianin’s compound and its analogues. This section also describes desorption studies of the new inclusion compound, as well as the known thiol analogue of Dianin’s compound. Systematic characterisation of these desorbed phases has raised interesting fundamental questions about desolvation processes in general. The second section constitutes the major portion of the work. A series of related isostructural coordination metallocycles were synthesised and their structure-property relationships were investigated using a variety of complementary techniques. These metallocyclic compounds all crystallise as solvates in their as-synthesised forms, and different results are obtained upon desolvation of the materials. In each case, desolvation occurs as a single-crystal to single-crystal transformation and three new “seemingly nonporous” porous materials were obtained. A single-crystal diffraction study under various pressures of acetylene and carbon dioxide was conducted for one of the porous metallocycles. This enabled the systematic study of the host deformation with increasing equilibrium pressure (i.e. with increasing guest occupancy). The observed differences in the sorption behaviour for acetylene and carbon dioxide are discussed and rationalised. Gravimetric gas sorption isotherms were also recorded for the three different porous materials and the diffusion of bulkier molecules through the host was also investigated structurally. Finally, a possible gas transport mechanism is postulated for this type of porous material (i.e. seemingly nonporous), and this is supported by thermodynamic and kinetic studies, as well as molecular mechanics and statistical mechanics simulations.
AFRIKAANSE OPSOMMING: Die primêre doel van die werk was om nuwe poreuse materiale te berei en deur die toepassing van beginsels van kristalmanipulasie (E. crystal engineering) te ondersoek. Beide organiese- en metaal-organiese sisteme is bestudeer en die werk kan in twee kategorieë verdeel word: 1. Die kristalmanipulasie van Dianin se verbinding, ’n bekende organiese gasheer. 2. Die ontwerp en sintese van ’n reeks verwante poreuse koördinasieverbindings wat uit diskrete, binukleêre metallosiklieseverbindings bestaan. Die eerste deel handel oor die sintetiese verandering van Dianin se verbinding om ’n nuwe klatraatgasheer met ’n veranderde spleetgrootte te vorm. Alhoewel hierdie studie nie daarin geslaag het om die gasheer in sy poreuse “gas(E. guest)-vrye” vorm te isoleer nie, het die werk ’n nuwe chirale gasheerraamwerk aan die lig gebring. Die chirale gasheerraamwerk rig gas(E. guest)molekules in eendimensionele kolomme op ’n polêre wyse en gevolglik vertoon die materiaal nie-linieêre optiese eienskappe. Hierdie resultaat is ongekend in die lang geskiedenis van kristalmanipulasie van Dianin se verbindings en sy analoë. Hierdie afdeling beskryf ook die desorpsiestudies van die nuwe gasheer, en die tiol-afgeleide van Dianin se verbinding. Die sistematiese karakterisering van hierdie fases na desorpsie het fundamentale vrae na vore gebring oor desorpsieprosesse oor die algmeen. Die tweede afdeling maak die grootste gedeelte van die werk uit. ’n Reeks verwante isostrukturele ringvormige koördinasieverbindings is gesintetiseer en hul struktuureienskap verhoudings is deur ’n verskeidenheid komplementêre tegnieke ondersoek. Hierdie metallosiklieseverbindings kristalliseer almal in gesolveerde toestand vanaf sintese en verskillende resultate word verkry wanneer die verbinding desorpsie ondergaan. In alle gevalle vind gas(E. guest)desorpsie as enkel-kristal na enkel-kristal omsettings plaas en drie nuwe ‘oënskynlik nie-poreuse’ poreuse materiale is bekom. ’n Enkelkristal diffraksiestudie onder verskeie gasdrukke is met asetileen en koolstofdioksied uitgevoer vir een van die poreuse metallosiklieseverbindings. Dit het die geleentheid geskep om die mate waartoe die gasheer as gevolg van verhoogde ewewigsdruk vervorm (en dus toename in gasheerbesetting), sistematies te bestudeer. Die waargenome verskille in sorpsie-optrede vir asetileen en koolstofdioksied word bespreek en verklaar. Gravimetriese gassorpsie isoterme is ook vir die drie poreuse materiale verkry en die diffusie van groter molekules deur die gasheer is struktureel ondersoek. Laastens word ’n moontlike gasoordragmeganisme vir hierdie tipe poreuse (i.e. oënskynlik nie-poreuse) materiale gepostuleer. Hierdie bespreking word deur termodinamiese en kinetiese studies aangevul, sowel as molekulêre-meganika en statisties-meganiese studies.

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Elbakush, Rasha Elmheidi. "A crystal engineering study of selected sulfa drugs and trimethoprim." Thesis, University of the Western Cape, 2014. http://hdl.handle.net/11394/4651.

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Magister Pharmaceuticae - MPharm
The objective was to prepare new solid phases, i.e. co-crystal forms, of two sulfa antibiotic drugs (sulfamethoxazole and sulfasalazine) with trimethoprim and fourteen potential co-formers with GRAS status. Trimethoprim was chosen for its synergistic effects with both sulfa drugs and the other co-formers were selected in an attempt to improve the physicochemical properties of the antibiotics. A variety of co-crystallization techniques, including solvent assisted grinding, slow evaporation, slurry method and solidification of the melt were used to obtain these results. From these methods, three new solid phases were successfully isolated for the sulfamethoxazole antibiotic, viz. sulfamethoxazole-benzoic anhydride (SMZ-BAN) co-crystal by the slurry method, amorphous sulfamethoxazole-trimethoprim (SMZ-TMP) form by solidification of the melt and amorphous sulfamethoxazole-oxalic acid (SMZ-OA) by slow evaporation. For the sulfasalazine antibiotic, co-crystallization experimentation produced, sulfasalazine-trimethoprim salt (SSZ-TMPs) by slow evaporation, sulfasalazine-trimethoprim co-crystal (SSZ-TMP) by solvent assisted grinding and sulfasalazine-nicotinamide co-crystal (SSZ-NC) by solidification of the melt. Of these six compounds subjected to single crystal X-ray analysis, only one of their structures was elucidated i.e. the salt, SSZ-TMPs. Different techniques that were used to assess the thermal behaviour of the products included hot stage microscopy, differential scanning calorimetry and thermogravimetric analysis. FTIR provided information on the purity of the compounds and the suggested host-guest interaction sites. X-ray powder diffraction supported the determination of the new phase comparative to the parent compounds. Finally dissolution testing was carried out for successful candidates with encouraging recommendations for future work.

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Greer, Heather F. "Electron microscopy of crystalline solids and non-classical crystal growth." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4127.

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This project concerns the non-classical crystal growth of various porous and non-porous materials. In order to determine their crystal growth mechanism, the reaction was stopped at several different reaction times with the size, morphology, crystal structure and orientation of the particles analysed using scanning electron microscopy and high resolution transmission electron microscopy as the principal characterisation techniques. Other techniques used include X-ray diffraction, energy dispersive X-ray spectroscopy, selected area electron diffraction and thermal gravimetric analysis. Selected biomimetic systems include the early stage crystal growth of ZnO/gelatin composite twin-crystals and the time dependent microstructural evolution of CaCO₃/gelatin composite particles from spherulites into rods. Further investigations of the role of gelatin molecules were carried out by replacing gelatin by gum arabic. Using knowledge gained from synthetic systems, several travertine crust specimens collected from hot springs were investigated to gain an insight into the possible formation mechanisms of naturally occurring biominerals. Another form of ZnO investigated was the formation of core-shell ZnO hexagonal microdisks and selective dissolution of their core to form microstadiums followed by the selective growth of nanorods and nanocones onto the columnar surfaces of the microstadiums to generate branched-microstadiums. The formation mechanism of ultrasonically prepared BiOBr displaying a flower-like architecture was investigated. These BiOBr assemblies are found to exhibit excellent photocatalytic activity and stability during the photodegradation of Rh.B under visible-light irradiation. Finally mesoporous silicate plates displaying a single crystal-like property were re-investigated to clarify whether the previously reported mesoporous silicate plates exhibiting a single crystalline property were one-phase materials or a composite of non-crystalline mesoporous silicate and crystalline zeolite.

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Ma, Jinge. "Design of Frequency Output Pressure Transducer." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804933/.

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Piezoelectricity crystal is used in different area in industry, such as downhole oil, gas industry, and ballistics. The piezoelectricity crystals are able to create electric fields due to mechanical deformation called the direct piezoelectric effect, or create mechanical deformation due to the effect of electric field called the indirect piezoelectric effect. In this thesis, piezoelectricity effect is the core part. There are 4 parts in the frequency output pressure transducer: two crystal oscillators, phase-locked loop (PLL), mixer, frequency counter. Crystal oscillator is used to activate the piezoelectricity crystal which is made from quartz. The resonance frequency of the piezoelectricity crystal will be increased with the higher pressure applied. The signal of the resonance frequency will be transmitted to the PLL. The function of the PLL is detect the frequency change in the input signal and makes the output of the PLL has the same frequency and same phase with the input signal. The output of the PLL will be transmitted to a Mixer. The mixer has two inputs and one output. One input signal is from the pressure crystal oscillator and another one is from the reference crystal oscillator. The frequency difference of the two signal will transmitted to the frequency counter from the output of the mixer. Thus, the frequency output pressure transducer with a frequency counter is a portable device which is able to measure the pressure without oscilloscope or computer.

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Saito, Kaichi. "Real crystal structure related to superconductor properties of YBa₂Cu₃O₇₋{delta} single crystals /." Zürich, 1997. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12105.

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41

Pokhrel, Chandra Prasad. "Crystal growth and charge carrier transport in liquid crystals and other novel organic semiconductors." [Kent, Ohio] : Kent State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1254234736.

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Thesis (Ph.D.)--Kent State University, 2009.
Title from PDF t.p. (viewed April 1, 2010). Advisor: Brett Ellman. Keywords: Laser; Charge generation; Charge transport; Mobility; Trapping; Space charge; Hopping; Tunneling; Lattice vibration; Exciton; Polaron; HUMO; LUMO; Action Spectrum; Quantum efficiency; Crystal Growth; Liquid crystal; Disordered medium. Includes bibliographical references.

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42

Levkovitch, Vladislav. "Classical and extended crystal-plasticity and its application to fatigue of FCC single crystals." Dortmund : V. Levkovich, 2005. http://d-nb.info/997648155/34.

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43

Chen, Parry. "Group velocity analysis of metamaterial photonic crystals and multipole simulation of photonic crystal slabs." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10525.

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Group velocity analysis of metamaterial photonic crystals and multipole simulation of photonic crystal slabs Periodicity is a feature of two topical areas of optics, photonic crystals and metamaterials. Photonic crystals scatter passing light coherently, introducing structural dispersion and creating band gaps where light cannot propagate. Metamaterials use resonant structures much smaller than the wavelength to produce negative effective refractive indexes. When metamaterials are constituents of photonic crystals, new phenomena arise. Firstly, new band gaps appear whenever the average refractive index is zero, occurring independently of Bragg reflections. However, only one dimensional examples have been reported, and its existence in higher dimensions is unknown. Secondly, the group velocity of dispersion relations can be infinite and turn negative, which violates conservation theorems obeyed by lossless structures. These open questions are resolved by using multipole methods, a two dimensional method specialized cylindrical inclusions. Analytical dispersion relations are derived for long wavelengths, demonstrating that zero average refractive index is neither necessary nor sufficient to obtain band gaps. Then, an analytical criterion for infinite group velocity points is derived, existing whenever the modal field is balanced between the positive and negative group index constituents of a photonic crystal. To derive this condition, an analytical tool is developed to calculate group velocities from modal field distributions and material parameters in general lossy dispersive periodic media. Finally, the strengths of the multipole method are applied to simulate a widely fabricated photonic crystal structure: the planar dielectric slab periodically perforated with cylindrical holes. Two structural symmetries are exploited, the vertical translational invariance of the slab, and the rotational invariance of the inclusions, to create a rapidly convergent numerical method. Extensions of the method are possible to defect structures and plasmonic extraordinary transmission gratings.

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44

Asmadi, Aldi, M. A. Neumann, John Kendrick, P. Girard, M.-A. Perrin, and Frank J. J. Leusen. "Revisiting the Blind Tests in Crystal Structure Prediction: Accurate Energy Ranking of Molecular Crystals." American Chemical Society, 2009. http://hdl.handle.net/10454/4727.

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no
In the 2007 blind test of crystal structure prediction hosted by the Cambridge Crystallographic Data Centre (CCDC), a hybrid DFT/MM method correctly ranked each of the four experimental structures as having the lowest lattice energy of all the crystal structures predicted for each molecule. The work presented here further validates this hybrid method by optimizing the crystal structures (experimental and submitted) of the first three CCDC blind tests held in 1999, 2001, and 2004. Except for the crystal structures of compound IX, all structures were reminimized and ranked according to their lattice energies. The hybrid method computes the lattice energy of a crystal structure as the sum of the DFT total energy and a van der Waals (dispersion) energy correction. Considering all four blind tests, the crystal structure with the lowest lattice energy corresponds to the experimentally observed structure for 12 out of 14 molecules. Moreover, good geometrical agreement is observed between the structures determined by the hybrid method and those measured experimentally. In comparison with the correct submissions made by the blind test participants, all hybrid optimized crystal structures (apart from compound II) have the smallest calculated root mean squared deviations from the experimentally observed structures. It is predicted that a new polymorph of compound V exists under pressure.

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45

Melotti, Claudio <1983&gt. "Long-time behavior of solutions to the system of crystal acoustics for tetragonal crystals." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3673/1/melotti_claudio_tesi.pdf.

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46

Melotti, Claudio <1983&gt. "Long-time behavior of solutions to the system of crystal acoustics for tetragonal crystals." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3673/.

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VIDAL, AUGUSTO T. "Sintese e crescimento de cristais fluoretos dopados com terras raras: LiCAF:Er e BLF:TR (TR = Yb sup(3+), Ce sup(3+), Nd sup(3+))." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10970.

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Made available in DSpace on 2014-10-09T12:46:16Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:01:47Z (GMT). No. of bitstreams: 1 07973.pdf: 3168450 bytes, checksum: 8bf87743d796e20893798cadfbfad208 (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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48

Kurz, GuÌˆnter. "Hydrodynamics of defects in nematic liquid crystal films." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313591.

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49

Merlin, Jessica M. "SURFACE MEDIATED NONLINEAR OPTIC EFFECTS IN LIQUID CRYSTALS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=case1169755107.

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50

Greiner, Daniel Joseph. "Influence of fluorine versus hydroxzyl content on the optics of the amblygonite-montebrasite series." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/50060.

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For 11 crystals of the amblygonite-montebrasite series LiAlPO₄(F,OH) ranging in composition from 4.0 to 91.8 mole percent fluorine with only two containing significant sodium, 2V and principal refractive indices were determined to 0.5° and 0.0005, respectively, by spindle-stage methods. If F < 60 mole percent, as is true for the vast majority of natural specimens, fluorine can usually be estimated to within 2 mole percent from the equation F = -66.3 + 1.08 * 2V_Z as well as from similar regression equations involving the refractive indices α, β, and γ. Above 60 mole percent F, the optical properties are less sensitively (and non-linearly) related to fluorine content. Estimates of F proved feasible despite significant substitution of Na for Li. By contrast, this substitution may introduce significant errors when estimating F by methods involving lattice parameters. Progressive substitution of (OH), a natural dipole involving a covalent bond, for the relatively non-polarizable F anion caused all three principal refractive indices to increase; γ increases more than α or ß because its corresponding principal vibration direction Z becomes sub-parallel to the O···H vector in the structure as (OH) content increases.
Master of Science
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