Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 110 for “"CRYSTALLINE STRUCTURE"”.
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Investigation of thermal decomposition as the cause of the loss of crystalline structure in sucrose, glucose, and fructose
… Scanning Calorimetry. The sugar loses its crystalline structure (commonly termed melting) by adsorbing heat energy, which yields the critical parameters of the resultant melting peak, i.e., the onset melting temperature (Tm onset), the peak melting temperature (Tm peak), and the enthalpy of …
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Growth of Semiconductor Thin Films by Pulsed Laser Deposition
… and ellipsometry were used to analyze the structures and properties of ZnO and SnO2 thin films. The critical temperature required to fabricate a crystalline ZnO thin film by pulsed laser deposition was found and has been confirmed. For the SnO2 thin film, the critical temperature required …
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Physicochemical and tableting properties of crystallised and spray-dried phenylbutazone containing polymeric additives. Effect of polymeric additives (hydroxypropyl methylcellulose and a polyoxyethylene-polyoxypropylene glycol) on the crystalline structure, physicochemical properties and tableting behaviour of crystallised and spray-dried phenylbutazone powders
The physicochemical properties of a drug affect to a large extent its subsequent biological absorption and bioavailability profile. Considerable pharmaceutical interest is therefore directed torwards the improvement of drug dissolution characteristics of drugs with low aqueous solubility. This …
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Design, Analysis, and Application of Architected Ferroelectric Lattice Materials
… to the piezoelectric properties, in traditional crystalline ferroelectric materials are determined by their inherent crystalline structure. This restriction limits the tunability of their piezoelectric properties. In the present work, ferroelectric lattice materials capable of a wide range of …
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Investigating the loss of crystal structure in carbohydrate materials
… could not be applied during the loss in crystal structure event, since the modulated heating rate cannot be controlled during the loss of crystal structure. The quasi-isothermal MDSC yielded important information in regards to the reversing heat capacity (Cp) signal. If the reversing Cp signal …
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Virus-enabled synthesis of titanium oxide nanowires
… formation, and XRD analysis identified the crystalline structure as anatase.
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Investigations of the quantum Hall effect in graphene
… we investigate the occurrence of various crystalline phases in the first three Landau levels; we determine which crystalline structure is energetically favorable as the filling factor is varied. In this thesis, we begin with a review of the quantum Hall effect in the two-dimensional …
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Energy storage and conversion applications of conductive metal-organic frameworks
Establishing catalytic structure-function relationships enables optimization of the catalyst structure for enhanced activity, selectivity, and durability against reaction conditions and prolonged catalysis. One class of catalysts that could benefit from systematic optimization is non-platinum group …
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An attempt to separate and identify "Hadromal"
… work was done in an effort to obtain sufficient crystalline material to identify. This was only partially realized. It was possible to obtain crystals in a yellow oil by extracting the hadromal mixture with ligroin. These crystals were aldehydic in nature. Because of the large amount of oil …
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Growth and characterizations of two-dimensional metal-organic frameworks
… (MOFs) are a class of porous materials with a crystalline structure that can be designed based on extremely tunable building blocks of organic molecules and metal ions. They are typically insulators but making them [pi]-conjugated with two-dimensional structure results in high electrical …
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Structure and Phase Transformation of Nanocrystalline and Amorphous Alloy Thin Films
The systematic study on the structure and morphology of Ag-Si alloy thin films shows nanocrystalline Ag clusters embedded in amorphous Si matrix for samples of different compositions and thicknesses. Ag cluster sizes increase from 2.5 nm to 3.5 nm as annealing temperature increases from room …
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Aging and Barkhausen noise in the relaxor ferroelectrics
"Relaxor ferroelectrics are disordered crystalline materials whose polar order is limited to mesoscopic-scaled nanodomains. There is no ferroelectric phase transition, but a faster than Arrhenius cooperative freezing into a glassy relaxor regime instead. It is not understood how the random fields …
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An investigation into Manganese(2+) interferences and retrospective dose assessment of shelled species using EPR spectroscopy
… causing Mn²⁺ accumulation in shells including crystalline structure and animal habitat. Inductively coupled plasma - optical emission spectroscopy (ICP-OES) was used to determine the Mn²⁺ concentrations in shells of thirteen species. A methodology to quantitatively compare Mn²⁺ concentrations …
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ZnO Nanostructures: Low-Temperature Synthesis, Characterisation, Their Potential Application as Gene-Delivery Tools
… metal oxide nanomaterials, zinc oxide (ZnO) nanostructures are one of the most important nanomaterials in today’s nanotechnology research. Over the past several decades, ZnO nanostructures have been extensively investigated for their extraordinary physical and chemical characteristics and also …
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Molecular order at polymer surfaces via X-ray photoelectron spectroscopy
… forms, such as preferential segregation of a crystalline block to the surface, segregation of a component of different crystalline structure to the surface or orientation of a backbone segment of the polymer towards the surface of the specimen. Polyethylene terephthalate shows an increasing …
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Emergent Critical Phases in Strongly Correlated Low-Dimensional Magnetic Systems
… pressure induced dimensionality crossover, crystalline structure change, insulator-to-metal transitions and the emergence of novel magnetic phases and superconductivity. Solving high-pressure structure models, particularly in terms of interplanar stacking geometry, has posed challenges due …
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A Study of Permalloy (Nickel(81)iron(19)) Nanoparticles as Possible Qubits
… and growth process, the nanoparticles have a polycrystalline structure. Several heating methods are employed in an attempt to recrystallize the nanoparticles. In the end, ultrafast heating with a femtosecond laser system is used to form single crystal nanoparticles. The wavelength of the laser is …
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Precursor gas comparison for the growth of silicon carbide fibers via laser chemical vapor deposition
… deposited SiC fiber composition, fiber microstructure, and fiber mechanical properties (ambient temperature failure stress in tension) were compared using two different precursor gases - Tetramethylsilane (TMS) and Dimethylsilane (DMS) – using laser chemical vapor deposition (LCVD). Each set …
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Microwave-Assisted Conversion of Sucrose into 5-Hydroxymethylfurfural over Acidic Nanoporous Materials
… the poor solubility of cellulose and its robust crystalline structure, current methods available to degrade cellulose into these biofuel precursors are costly, result in low yields along with a large amount of waste. Generally, fructose is the preferred feedstock for the synthesis of HMF with …
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Instrumentation For the Study of Tantalum Diffusion Barriers Between Silicon Substrates and Copper Films
… currently believed that grain boundary density, crystalline structure, and film purity are some of the factors involved in the material's ability to be a successful diffusion barrier. The purpose of this work is to produce the necessary instrumentation to control the growth of both the diffusion …
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