Дисертації з теми "Crystalline properties"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Crystalline properties".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Svensson, Erik. "Crystalline properties of starch." Lund : Lund University, 1996. http://books.google.com/books?id=VOdqAAAAMAAJ.
Повний текст джерелаDimitrievska, Mirjana. "Crystalline and vibrational properties of kesterites." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/395179.
Повний текст джерелаEl objetivo principal de esta tesis es mejorar el conocimiento de las propiedades fundamentales de los compuestos de kesterita (Cu2ZnSnS4 and Cu2ZnSnSe4) y sus soluciones solidos Cu2ZnSn(S,Se)4 para uso como absorbedor en células solares. Esto constituye de la caracterización completa de las propiedades estructurales y vibracional utilizando la espectroscopia Raman. Adicionalmente, está el desarrollo de metodologías basado en Raman para la valoración composicional de estos materiales. Estos resultados están destacados en una serie de artículos publicados en revistas de peer-review de alto impacto. Un análisis completo de todos los modos activos de Raman de los compuestos estequiometricas de kesterita se realizó utilizando seis diferentes longitudes de onda de excitación, desde el infrarrojo hasta la ultravioleta. A partir de la base de simulaciones de primeros principios, los desplazamientos normales de cada modo Raman fueron calculados y dan un conocimiento útil sobre la participación de átomos en vibraciones correspondientes a diferentes modos. Un énfasis especial se da a la investigación de la dinámica de defectos en las kesteritas, en particular a la identificación experimental de los defectos y sus efectos sobre las propiedades optoelectrónicas, incluso el rendimiento, de dispositivos de células solares. También se desarrollo de una metodología para la valoración quantativa de la composición de aniones de soluciones solidos de Cu2ZnSn(S,Se)4 utilizando la espectroscopia Raman. Esta metodología se basa en la analisis de la intensidad integral de las bandas Raman más sensibles a vibraciones de los aniones. Por último, hay un estudio teórica y experimental del aumento en intensidad de los modos Raman de compuestos ZnSSe, bajo varias condiciones de resonancia, lo cual resulta en una mejora del conocimiento de la parte que juega los estados electrónicos de los calcogenuros en la interacción de fotón-materia. En conclusión, el trabajo presentado en esta tesis es una contribución significante al estudio de las propiedades fundamentales de los materiales en general, y los compuestos de kesterita en particular. Adicionalmente, debido al uso complementario de la espectroscopia Raman con otras técnicas de caracterización, estos métodos puedan resultar en ser muy útiles en estudios de estructura/función de otros compuestos multinarios, los cuales están ganado más interés para aplicaciones electrónicas.
Budgell, Derek Richard. "Liquid crystalline properties of ethyl cellulose." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74271.
Повний текст джерелаThe onset of mesophase formation is studied by employing literature data on the viscosity/molar mass relationship of several cellulose derivatives, including EC in several solvents, to calculate their molecular dimensions by a recent hydrodynamic theory. The phase separation behavior is compared with the predictions of theories for both freely-jointed and wormlike chains.
The effects of solvent and degree of substitution (DS) on the cholesteric structure are assessed by studying the chiroptical properties using Circular Reflectance and Optical Rotatory Dispersion (ORD) techniques. The DS strongly influences the helicoidal twist sense, reflection wavelength and response of the reflection wavelength to changes in temperature. Mesophases and cholesteric films of the methyl and n-butyl derivatives of EC are also investigated. The ORD spectra of isotropic EC solutions are found to be strongly influenced by the solvent employed.
Di, Lollo Antonio B. "Thermal and surface properties of crystalline and non-crystalline legume seed proteins." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59973.
Повний текст джерелаGlucose and mannose were the major sugars found in the isolates. Bipyramidal and spheroidal microstructures with higher protein contents generally had greater mannose content and lower glucose content. Differences in enthalpy of denaturation $( Delta$H), surface tension decay curves, surface hydrophobicities, and foam expansions were observed with isolates of different microstructures. Corresponding differences in molecular structure were not, however, detected by FT-IR spectroscopy. Using statistical analysis, a relationship between foam expansion and the $ Delta$H, solubility, surface hydrophobicity and surface tension of the isolates was obtained. Preliminary results suggest that the removal of carbohydrate influenced the physico-chemical properties of the protein.
Heng, Jerry Yong Yew. "Anisotropic surface properties of crystalline pharmaceutical solids." Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/8843.
Повний текст джерелаThies, Jens Christoph. "Optical properties of chiral liquid crystalline polymers." Thesis, Heriot-Watt University, 1998. http://hdl.handle.net/10399/590.
Повний текст джерелаHaws, Christine Margaret. "Selected physical properties of liquid crystalline polysiloxanes." Thesis, Durham University, 1989. http://etheses.dur.ac.uk/6496/.
Повний текст джерелаSweed, Muhamed. "Free volume properties of semi-crystalline polymers." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6597.
Повний текст джерелаENGLISH ABSTRACT: Positron annihilation lifetime spectroscopy (PALS) is well established as a novel method currently available for the study of polymers at a molecular level because of its sensitivity to the microstructural changes in the polymer matrix. The technique provides unique, but limited, information of the solid state structure – primarily on the nature of the free volume (or unoccupied space) in the polymer due to the less dense packing of polymer chains relative to in other solid materials. In the case of completely homogeneous polymer materials the measurement and interpretation of the positron annihilation parameters is relatively simple. However, in the case of polymers with more complex morphologies the situation becomes less clear. This is due to the possibility of the formation, localization and subsequent annihilation of o-Ps (ortho-positronium) within different areas of the complex morphology. This can result in more than one o-Ps lifetime component being present, and each of the different components corresponds to areas with differing types and amounts of 'open spaces'. In this study a detailed and systematic approach was taken to study the positron annihilation parameters in various semi-crystalline polymers and to correlate these to the chain structure and morphology of the materials. The study focused specifically on polyolefin polymers as these are the most widely used semi-crystalline materials, but more importantly, they offer the possibility to produce a variety of morphological complexity by simple manipulation of the chain structure – while there is essentially no difference in the chemical composition of the materials. The copolymers were selected to study the influence of short-chain branching (amount and length), short-chain branching distribution and tacticity on the morphology, and subsequent positron annihilation lifetime parameters. Three separate topics were addressed. First, preparative temperature rising elution fractionation was used to isolate polymer samples that are homogeneously crystallisable and to produce a series of polymers with differing chain structure and resultant morphologies. Second, additional series were produced by removing specific crystallisable fractions from the bulk materials. Third, the temperature variation of the samples as they approach and go through the crystalline melting point was studied. All the raw positron data were found to be best fitted with a four-component positron annihilation lifetime analysis. The longest lifetime (which is attributed to annihilation of o-Ps in the amorphous phase of the materials) showed systematic variations with the degree and nature of the short-chain branding, tacticity variation, a combination of both short-chain branching and tacticity, and changes in the amorphous phase as a result of heating. The third lifetime component (which is attributed to o-Ps annihilation in or around the crystalline areas of the materials) showed less variation across the sample series. Typically, greater variations were observed in the propylene copolymers than in the ethylene copolymers, which are reflective of the more complex chain structure and corresponding morphology in the propylene copolymer series. Direct evidence for a contribution from the nature of the amorphous phase to the bulk microhardness of the sample was also found.
AFRIKAANSE OPSOMMING: Positronvernietigingsleeftydspektroskopie (PALS) is goed gevestig as ‘n nuwe metode vir die studie van polimere op molekulêrevlak agv die sensitiwiteit van die metode vir mikrostrukturele veranderings in die polimeermatriks. Hierdie tegniek verskaf unieke, maar beperkte, inligting aangaande die vastetoestandstruktuur – veral aangaande die aard van die vryevolume (of onbesette spasie) in die polimeer as gevolg van die minder digte verpakking van polimeerkettings relatief tot in ander vastestowwe. In die geval van volledig homogene polimeriese materiale is die meet en interpretasie van die positronvernietigingsparameters relatief eenvoudig. Maar in die geval van polimere met meer komplekse morfologieë is die situasie minder duidelik. Die rede hiervoor is die moontlikheid vir die formasie, lokalisering en gevolglike vernietiging van o-Ps (orto-positronium) in die verskillende areas van die komplekse morfologie. Dit kan tot gevolg hê dat meer as een o-Ps komponent teenwoordig is en waar elk van die verskillende komponente ooreenstem met areas met verskillende tipes en hoeveelhede 'oop spasies'. In hierdie studie is ‘n sistematiese, in-diepte benadering gebruik om die positronvernietigingsparameters in verskeie semikristallyne polimere te bestudeer en hulle te korreleer met dié van die kettingstruktuur en die morfologieë van die materiale. Hierdie studie het spesifiek gefokus op poliolefiene aangesien hulle die mees algemene semikristallyne materiale is wat gebruik word en, nog meer belangrik, hulle bied die geleentheid om verskeie komplekse morfologieë te lewer dmv eenvoudige manipulasie van die kettingstrukture – terwyl daar basies geen verandering in die chemiesesamestelling van die materiale is nie. Die kopolimere is gekies om die invloed van kort-ketting vertakking (lengte en hoeveelheid), kort-ketting vertakking verspreiding en taktisiteit op die morfologie en vervolgens die positronvernietigingsleeftyd parameters te bestudeer. Drie onderwerpe is aangespreek. Eerstens, preparatiewe temperatuurstygingelueringsfraksionering (prep-TREF) is gebruik om polimeermonsters wat homogeenkristalliseerbaar is te isoleer om sodoende 'n reeks polimere met verskillende kettingstrukture, en gevolglike morfologieë, te lewer. Tweedens, 'n addisionele reekse monsters is berei deur die verwydering van spesifieke kristalliseerbare fraksies vanaf die grootmaatmonsters. Derdens, die temperatuurverandering van die monsters wanneer die monsters naby aan die kristallyne smeltpunt is en wanneer hulle deur die kristallyne smeltpunt gaan is bestudeer. Daar is bevind dat alle rou positrondata ten beste gepas het in 'n vier-komponent positronvernietigingsleeftydanalise. Die langste leeftyd (wat toegeskryf is aan vernietiging van o-Ps in die amorfe fase van die materiaal) het sistematiese variasies getoon met die volgende: hoeveelheid en aard van die kort-kettingvertaking, verandering in taktisiteit, 'n kombinasie van beide kort-kettingvertakking en taktisiteit en veranderings in die amorfiesefase as gevolg van verhitting. Die derde leeftyd komponent (wat toegeskryf is aan die o-Ps vernietiging in of rondom die kristallyne areas van die materiale) het minder variasie in hierdie reeks monsters getoon. Daar is tipies meer variasie waargeneem in die propileenkopolimere as in die etileenkopolimere, wat ’n weerspieëling is van die meer komplekse kettingstruktuur en ooreenstemmende morfologie in die propileenkopolomeerreeks. Direkte bewys vir 'n bydrag van die aard van die amorfe fase tot die grootmaat mikrohardheid van monsters is ook bevind.
JÃnior, Diniz Maciel de Sena. "Vibrational and Thermal Properties of Crystalline Topiramate." Universidade Federal do CearÃ, 2008. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1372.
Повний текст джерелаThe scientific interest on molecular crystals stems from their great versatility and ease of processing. For pharmaceutically active ingredients, the structure-activity relationship is of major importance. Topiramate, a white and crystalline solid, is a powerful drug efficiently employed to control epilepsy symptoms. The mechanism of action involves a negative modulatory effect on the AMPA/kainate subtypes of glutamate receptors and some types of voltage-gated Na+ and Ca2+ channels, and a positive modulatory effect on some types of GABAA receptors and at least one type of K+ channels in neurons. Despite its pharmacological attributes, the lack of publications regarding its physical-chemical properties in the literature is apparent. In order to fill this gap, a research comprising vibrational spectroscopy techniques (Raman and infrared), thermal analysis (TGA/DTA/DSC), and theoretical calculations, was carried out. With the aid of calculations employing density functional theory (DFT), most of the observed vibrational bands is assigned. Consideration of Raman spectra recorded at temperatures above and below room temperature, as well as under high hydrostatic pressures, indicated maintenance of the orthorhombic crystalline structure under the diverse thermodynamic conditions employed. Thermal analysis, however, showed that, after the melting point, the sample undergoes decomposition in a process comprising three stages, possibly initiated with loss of the sulfamate group by the molecule. This event inspired a theoretical study aimed at promoting the sulfamate group bond breakage in a controlled way by employing a laser instead of heat. This was accomplished by quantum dynamics simulations which showed that, by using a set of ultrashort pulses in the infrared region, it is possible to reach levels close to 70 % dissociation in less than 3 ps.
O interesse cientÃfico pelos cristais moleculares resulta da facilidade de processamento destes materiais, e de sua grande versatilidade. No caso de drogas, a relaÃÃo entre estrutura e atividade à de suma importÃncia. Topiramato, um sÃlido branco e cristalino, à um fÃrmaco utilizado com bastante eficiÃncia para controlar os sintomas da epilepsia. O mecanismo de aÃÃo envolve um efeito modulatÃrio negativo nos receptores de glutamato do subtipo AMPA/kainato e alguns tipos de canais de Na+ e Ca2+ voltagem-dependentes, bem como um efeito modulatÃrio positivo em alguns tipos de receptores GABAA e pelo menos um tipo de canal de K+ nos neurÃnios. A despeito de suas qualidades farmacolÃgicas, a escassez de trabalhos relacionados Ãs suas propriedades fÃsico-quÃmicas na literatura à evidente. Para ajudar a preencher esta lacuna, uma investigaÃÃo envolvendo tÃcnicas de espectroscopia vibracional (Raman e infravermelho), anÃlises tÃrmicas (TGA/DTA/DSC), e cÃlculos teÃricos, foi realizada. Com a ajuda de cÃlculos empregando a teoria do funcional de densidade (DFT), a atribuiÃÃo da maioria das bandas vibracionais observadas foi realizada. A observaÃÃo dos espectros Raman obtidos em temperaturas acima e abaixo da ambiente, bem como sob altas pressÃes hidrostÃticas, indicou que a estrutura cristalina ortorrÃmbica à mantida nas diferentes condiÃÃes termodinÃmicas empregadas. A anÃlise tÃrmica, entretanto, mostrou que, apÃs a fusÃo, o material sofre decomposiÃÃo em um processo que envolve trÃs etapas, possivelmente iniciado com a perda do grupo sulfamato pela molÃcula. Este fato motivou um estudo teÃrico a fim de modelar a quebra da ligaÃÃo do sulfamato de maneira controlada, utilizando um laser em lugar de calor. Isto foi realizado com simulaÃÃes de dinÃmica quÃntica, que mostraram que, atravÃs da utilizaÃÃo de uma combinaÃÃo de pulsos ultracurtos na regiÃo do infravermelho, à possÃvel atingir nÃveis prÃximos a 70% de dissociaÃÃo em menos de 3 ps.
Watson, Greg. "Spectral properties of periodically modulated systems." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302889.
Повний текст джерелаWang, Haopeng. "Confined crystallization, crystalline phase deformation and their effects on the properties of crystalline polymers." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1246041849.
Повний текст джерелаVinh. "Optical properties of isoelectronic centers in crystalline silicon." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2004. http://dare.uva.nl/document/75308.
Повний текст джерелаSheppard, O. "Structural and liquid crystalline properties of ionic liquids." Thesis, Queen's University Belfast, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431482.
Повний текст джерелаHalliwell, Rebecca Amy. "Control of crystalline particle properties by spray drying." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28652.
Повний текст джерелаBanach, Michael James. "Alignment properties of liquid crystalline conjugated polymer films." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619834.
Повний текст джерелаGabaston, Laurence Isabelle. "Synthesis and properties of liquid crystalline conducting polymers." Thesis, Kingston University, 1996. http://eprints.kingston.ac.uk/20594/.
Повний текст джерелаLambe, Gillian Jane. "Synthesis and properties of liquid crystalline conjugated polymers." Thesis, Kingston University, 2003. http://eprints.kingston.ac.uk/20712/.
Повний текст джерелаMogri, Zen. "Gas transport properties of side-chain crystalline polymers /." Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3008396.
Повний текст джерелаPark, Seung Chul. "Study of optical properties of multi-crystalline Si and of heavily dislocated single-crystalline Si." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314286.
Повний текст джерелаShepherd, James Ellison. "An internal state variable based constitutive model for semi-crystalline polymers." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17638.
Повний текст джерелаJones, Christopher Wynne. "Structural and electronic properties of mixed metal oxides." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235645.
Повний текст джерелаClaesson, Hans. "Synthesis and Properties of Branched Semi-Crystalline Thermoset Resins." Doctoral thesis, KTH, Fibre and Polymer Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3583.
Повний текст джерелаThis thesis describes the synthesis and characterization ofbranched semi-crystalline polymers. Included in this work isthe SEC characterization of a series of dendrimers. Thebranched semi-crystalline polymers were synthesized in order toinvestigate the concept of their use as powder coatings resins.This concept being that the use of branched semi-crystallinepolymers in a UV-cured powder coating system may offer a lowertemperature alternative thus allowing the use of heat sensitivesubstrates and the added benefit of a reduced viscositycompared to linear polymers.
A series of branched poly(ε-caprolactone)s (PCL)(degree of polymerization: 5-200) initiated from hydroxylfunctional initiators were synthesized. The final architectureswere controlled by the choice of initiator structure;specifically the dendritic initiators yielded starbranchedPCLs while the linear initiator yielded comb-branchedPCLs. The dendritic initiators utilized were: (1) a3rd-generation Boltorn H-30, commercially availablehyperbranched polyester with approximately 32 hydroxyl groups,(2) a 3rd-generation dendrimer with 24 hydroxyl groups, and (3)a 3rd-generation dendron with 8 hydroxyl groups. Linear PCL wassynthesized for comparison. All dendritic initiators are basedon 2,2- bis(methylol) propionic acid. The comb-branchedpolymers were initiated from a modified peroxide functionalpolyacrylate. The resins were end-capped withmethylmethacrylate in order to produce a cross-linkable system.The polymers and films were characterized using 1H NMR, 13CNMR, SEC, DMTA, DSC, FT-IR, FT-Raman, rheometry and a rheometercoupled to a UV-lamp to measure cure behavior.
The star-branched PCLs exhibited considerably lowerviscosities than their linear counterparts with the samemolecular weight for the molecular region investigated (2-550kg mol-1). It was also found that the zero shear viscosityincreased roughly exponentially with M.
The PCL star-branched resins are semi-crystalline and theirmelting points (Tm) range from 34-50°C; films can beformed and cured below 80°C. The viscoelastic behaviourduring the cure showed that the time to reach the gel point, afew seconds, increased linearly with molecular weight. Thecrossover of Gand Gwas used as the gelpoint. Measurement of mechanical properties of films showedthat the low molecular weight polymers were amorphous whilethose with high molecular weight were crystalline after cure.The polymerization of 5,5-dimethyl-1,3-dioxane-2-one (NPC) fromoligo- and multifunctional initiators was evaluated utilizingcoordination and cationic polymerization. Two tin basedcatalysts, stannous(II) 2-ethylhexanoate and stannous(II)trifluoromethane sulfonate, were compared with fumaric acid.Fumaric acid under bulk conditions resulted in lowerpolydispersity and less chance of gelling. The synthesis ofstar-branched polymers was confirmed by SEC data. The starpolymers exhibited a Tg at 20-30°C and a Tm at about100°C.
All semi-crystalline resins exhibited a fast decrease inviscosity at Tm. Blends of combbranched semi-crystalline resinsand amorphous resins exhibited a transition behavior inbetweenthat of pure semi-crystalline resins and that of amorphousresins.
The SEC characterization of a series of dendrimers withdifferent cores and terminal groups showed that the core had animpact on the viscosimetric radius of the core while theterminal groups appeared to have no effect.
Keywords:star-branched, semi-crystalline,comb-branched, ring-opening polymerization,poly(ε-caprolactone), dendritic, thermoset, lowtemperature curing, powder coating, UVcuring,poly(5,5-dimethyl-1,3-dioxane-2-one), size exclusionchromatography, rheology, dendritic aliphatic polyester
Mcguire, Janine Gale. "Synthesis and properties of potentially liquid crystalline phosphorus compounds." Thesis, University of Central Lancashire, 2000. http://clok.uclan.ac.uk/20138/.
Повний текст джерелаWhitehead, Katherine Suzanne. "Polarised light emitting properties of liquid crystalline conjugated polymers." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269317.
Повний текст джерелаSakaida, Shun. "Stimuli-responsive properties of a downsized crystalline coordination framework." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263346.
Повний текст джерелаZhang, Heping. "Structure and properties of oriented thermotropic liquid crystalline polyesters and polyamides." Thesis, University of Leeds, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305812.
Повний текст джерелаNitsche, Robert. "Optical Properties of Organic Semiconductors: from Submonolayers to Crystalline Films." Doctoral thesis, [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=979835186.
Повний текст джерелаNitsche, Robert. "Optical Properties of Organic Semiconductors: from Submonolayers to Crystalline Films." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1147356837431-39487.
Повний текст джерелаDikeakos, Maria. "Electronic properties of amorphous and crystalline FexCo1-x-Zr2 alloys." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20141.
Повний текст джерелаRowland, Joanne. "Assessing changes in the surface properties of a crystalline material." Thesis, University of London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533545.
Повний текст джерелаCarpentier, Alice Ursula. "Hyperbranched polysiloxysilanes-liquid crystalline core-shell structures : preparation and properties." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/610.
Повний текст джерелаPickles, Adrian Philip. "The rheology, properties and morphology of thermotropic liquid crystalline polymers." Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317227.
Повний текст джерелаBarlow, Lyndsey J. "Thermal, mechanical and electrical properties of liquid crystalline polymer electrolytes." Thesis, University of Aberdeen, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401497.
Повний текст джерелаThadani, Shalini B. "Effect of crystalline-phase crosslinking on thermomechanical properties of a diacetylene-containing polyamide fiber." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/9252.
Повний текст джерелаKhamvongsa, Bryan. "Molecular control of liquid crystalline orientation of poly(2,6-benzoxazole)." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/8567.
Повний текст джерелаGreenstein, Abraham. "Analysis of thermal conductivity models with an extension to complex crystalline materials." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24710.
Повний текст джерелаCommittee Chair: Graham, Samuel; Committee Co-Chair: Nair, Sankar; Committee Member: Grover - Gallivan, Martha; Committee Member: McDowell, David; Committee Member: Schelling, Patrick; Committee Member: Zhang, Zhuomin
Roso, Casares Sergio. "Synthesis and gas sensing properties of single crystalline metal-oxide nanostructures." Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/402468.
Повний текст джерелаEn la presente tesis doctoral, se han producido diferentes tipos de nanoestructuras basadas en oxidos metalicos, como por ejemplo nanohilos de ZnO y ocaedros de In2O3, utilizando el método de Deposición Química de Vapor (CVD) a altas temperaturas. Para la detección de dióxido de nitrógeno, se ha descubierto que la respuesta de los nanohilos de ZnO está directamente correlacionada con la cantidad total de defectos presentes en el material. Cuanto mayor es el número de defectos, mayor es la respuesta al dióxido de nitrógeno. Sin embargo, para la detección de etanol, la muestra que contenía un número medio de defectos fue la que dio mejores resultados. Por lo que respecta a los octaedros de In2O3, podemos decir que los octaedros de In2O3 puro son excelentes candidatos para la detección de NO2, ya que poseen una excelente sensibilidad (0.43 ppb-1) a bajas temperaturas (130ºC), mientras que la respuesta a otros gases como H2 es dos órdenes de magnitud inferior en las mismas condiciones. Además, en presencia de humedad, se incrementa la sensibilidad a NO2 y, a la vez, se reduce la sensibilidad a H2, por lo que la selectividad hacia NO2 tambien se ve incrementada. Finalmente, utilizando la espectroscopia DRIFT, se ha analizado el In2O3 expuesto a 1 ppm de NO2 a diferentes temperaturas y se ha descubierto que el mecanismo propuesto para describir el proceso de senado es bastante más complicado que lo que se ha publicado hasta ahora. Como resultado de todos estos experimentos, se ha arrojado luz nueva sobre los mecanismos de sensado de los nanohilos de ZnO y los octahedros de In2O3 a diferentes temperaturas.
In the present doctoral thesis, several metal oxide nanostructures such as ZnO nanowires and In2O3 octahedra via a chemical vapour deposition (CVD) method at high temperatures. For the detection of nitrogen dioxide, it was found that the response of ZnO nanowires was directly correlated to the overall amount of defects of the material. The higher the number of defects is, the higher the response to nitrogen dioxide is. On the other hand, for the detection of ethanol, ZnO nanowires with an intermediate number of defects in which surface defects were dominant led to the best results. Additionally, regarding the In2O3 octahedra, we can say that pure In2O3 octahedra are excellent for detecting NO2 gas with an outstanding sensitivity (0.43 ppb-1) at low temperatures (130ºC), while the response to H2 remains two orders of magnitude lower under the same conditions. In addition, the presence of humidity increases the sensitivity to NO2 and, at the same time, reduces the response to H2, which results in an increased selectivity. Finally, by making use of the DRIFT spectroscopy, we have analyzed In2O3 material towards 1 ppm of NO2 at different temperatures and, it has been found that the mechanism proposed for the gas sensing is far more complicated than previously reported. As a result of these experiments, new light on the sensing mechanism of ZnO and In2O3 material towards NO2 gas at different temperatures has been shed.
Scribbins, Ashley Chandler. "Synthesis and properties of some novel liquid crystalline systems including metallomesogens." Thesis, Nottingham Trent University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389686.
Повний текст джерелаHasson, Craig. "Preparation and properties of liquid crystalline elastomers with chiral nematic structure." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326186.
Повний текст джерелаHogan, Sarah Eve. "Investigation of the amorphous and crystalline properties of lactose and raffinose." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268883.
Повний текст джерелаWaigh, Thomas Andrew. "The structure and side-chain liquid-crystalline polymeric properties of starch." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284951.
Повний текст джерелаWensley, Charles Alexander. "Processing and Properties of Amorphous NiW Reinforced Crystalline Ni Matrix Composites." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/30793.
Повний текст джерелаMaster of Science
Tsung-Wen, Huang, and 黃宗文. "Liquid Crystalline Properties of BisimidazoliumSalts with different anion Liquid Crystalline Properties of BisimidazoliumSalts with different anion Liquid Crystalline Properties of Bisimidazolium Salts with differen anion." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/95040985495612608455.
Повний текст джерела輔仁大學
化學系
93
The aim of this work is to synthesize and investigated liquid crystalline properties of bisimidazolium salts with different anions [(Im18)2Cn][X]2 n = 2, 3, 4, 5, 6, 8, 9, 10 ; X = PF6 and BF4 . The bisimidazolium salts with different anion were prepared by anion metathesis. These [(Im18)2Cn][X]2 salts have a liquid crystalline properties, most of these compounds exhibited SmA mesophase ; a small of these compounds exhibited smectic highly order mesophase. By the PXRD analysis we found that with the increase of n number, there are two kinds of situations of the d-spacing (from solid phase into liquid crystal phase). Liquid crystal behaviors of these compounds were investigated by differential scanning calorimetry, polarized optical microscopy and powder X-ray diffraction.
Hung, Ying Jer, and 黃英哲. "Electrorheological of Liquid Crystalline Polymer Properties." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/52767134547099036718.
Повний текст джерелаGuo, Zhen-Kuan, and 郭真寬. "Synthesis of liquid crystalline polymers and properties." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/60896405940478776305.
Повний текст джерелаTSENG, HSIAO-YI, and 曾效沂. "Synthesis and Properties of Liquid Crystalline Epoxy." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/16213962506794065654.
Повний текст джерела國立臺灣大學
材料科學與工程學研究所
86
The synthesis of two novel liquid crystalline epoxies, one based on Schiff b ase with azomethine linkage : 4,4''-bis(2,3-epoxypropoxy) benzylideneaniline(DG EAM), the other based on biphenyl mesogen : 4,4''-bis(2,3-epoxypropoxy)biphenyl (DGEBP), has been presented. DGEAM shows nematic mesophase while DGEBP with sm ectic phase from the observation of polarized optical microscope. These two li quid crystalline epoxies are cured by sulfanilamide(SAA) under proper curing c onditions and characterized with the use of dynamic mechanical analysis(DMA), thermomechanical analysis(TMA), thermogravimetric analysis(TGA) and X-ray diff raction. Liquid crystalline epoxies, DGEAM and DGEBP, have higher glass transi tion temperature(Tg) and lower thermal expansion coefficient(CTE) compared wit h the conventional DGEBA epoxy. The DGEAM, with the heat stability of the azom ethine linkage, has the lowest speed of degradation. The conventional epoxy,DG EBA, degrades fast due to the Bisphenol A segment. On the basis of X-ray diffr action analysis, the DGEAM-SAA is an isotropic epoxy thermoset. The DGEBP-SAA, on the contrary, is a liquid crystalline epoxy thermoset probably with the pr esvervation of smectic phase inside the network.
Sun, Shih Jien, and 孫時傑. "Synthesis and properties of liquid crystalline polycarbonates." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/28758202312275277094.
Повний текст джерелаJU, LEE YI, and 李宜儒. "Synthesis and Properties of Segmented Liquid Crystalline Polyurethane." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/31913024301319327400.
Повний текст джерела國立成功大學
化學工程學系
88
Abstract A series of mesogenic unit with biphenyl group as mesogen core and alkoxy group as flexible chain, 4,4’-bis(ω-hydroxyalkyloxy)-biphenyls, were synthesized , which included 4,4’-bis(2-hydroxyethoxy) biphenyl (BHEBP), 4,4’-bis(3-hydroxypropenoxy)biphenyl (BHPBP) and 4,4’-bis (6-hydroxyhexoxy) biphenyl (BHPBP) . FTIR , EA and H1-NMR were used to confirm their structures . The thermal behaviour and phase behaviour were characterized by DSC, optical microscopy and WXRD. Studies indicate that mesophase of the three mesogenic unit are all smectic G or smectic H and all trans conformation requires a 50°~60°tilt of the molecules in the smectic layers. Besides, the stability of the mesophase were BHHBP > BHEBP > BHPBP. BHPBP and BHHBP are used as the mesogenic unit in the synthesis of homopolyurethanes and copolyurethanes. Homopolyurethane P3 was observed to exhibit smectic-like phase , however , P6 was observed to exhibit crystalline phase only. All copolyurethanes are hard to recognize if the mesophase do exist by using optical microscopy.
Chang, Piao-Fu, and 張標富. "Physical Properties of Main-Chain Liquid Crystalline Polyurethanes." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/99726372720964243800.
Повний текст джерела元智大學
化學工程學系
91
In this study, we report physical properties of main-chain liquid crystalline polyurethanes. Thermotropic hard segment type liquid crystalline polyurethanes can be obtained by a step polyaddition reaction from mesogenic diols with diisocyanates. All the thermal decomposition behavior of polyurethanes are about 300℃. It shows that the technical application of polyurethanes is limited. In order to obtain polymers with a high application we became interested in the study of decrease of the hard segment melting points to enhance mesogenic temperature range △TLC (i.e. △TLC =Tm→TN-I). Phase segregation of polyurethanes was investigate by DSC, FTIR and POM. It was found that the temperatures of phase transitions depend on the amount of mesogenic diols substituted for 1,4-BD. They show a higher transition temperature (Tg and Tm) when the polyurethanes have been raised by the increase of the amount of mesogenic diols. The transition temperatures and the temperature ranges of mesophases also changed with the length of alkoxy spacer and the kind of diisocyanate. The longer the spacer length, the lower is the transition temperature. And MDIn shows a higher Td than that of TDIn.
Liao, Chi-Hung, and 廖啟宏. "Single Crystalline Zn2GeO4 Nanowires and Their Optoelectronic Properties." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/29688589495796884825.
Повний текст джерела國立交通大學
材料科學與工程學系所
101
In this work, Zn2GeO4 nanowires (NWs) have been successfully synthesized on Si (100) substrate through carbon thermal reduction and vapor-liquid-solid method. The diameters of the NWs are in the range of 80-150 nm with high aspect ratio (AR>100). The X-ray diffraction (XRD) peaks revealed that the phase is rhombohedral Zn2GeO4. High resolution transmission electron microscopy (HRTEM) indicated that the NWs are perfect single-crystalline with [110] growth direction. Moreover, the atomic resolution high-angle annular dark-field (HAADF) and bright field images of scanning transmission electron microscopy (STEM) can distinguish the different elements of atoms. They further clarified the structure of Zn2GeO4 and the position of elements located. The room temperature photoluminescence spectra of Zn2GeO4 NWs revealed high UV emission and broad blue emission. The UV emission was attributed to the Zinc interstitial, of which the intensity decreased as temperature increasing. Furthermore, we have fabricated the device to measure electrical properties of the single NW. The platinum electrodes of the device were deposited by focus ion beam (FIB). It is remarkable that individual Zn2GeO4 NW device exhibited excellent optoelectronic property with fast switching speed under 254 nm UV illuminations. The result showed that Zn2GeO4 NWs can be served as the building blocks for UV photodetectors. In addition, while exposing Zn2GeO4 NWs, which soaking in methyl orange solution. With short wavelength UV illumination, the methyl orange were degraded. This result showed that Zn2GeO4 NWs can be used in degrading organic pollutants. In conclusion, Zn2GeO4 NWs show highly potential applications in UV photodetectors and degradation of organic pollutants.