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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 26 for “"crystal nucleation"”.
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On Protein Crystal Nucleation Precursors
Protein crystallization is central to our understanding of molecular structures in biology, vital to industrial processes in the pharmaceutical industry, and increasingly appreciated as a critical block in understanding numerous disease pathologies. Although the nucleation process is critical in …
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Primary and secondary crystal nucleation of pharmaceutics
Control of the crystallisation process is essential in the consistent and reliable production of many particulate materials in the pharmaceutical and chemical industries. Crystal Nucleation defines the crystal size distribution of the obtained crystal population affecting downstream operations. The …
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Phase behaviour and crystal nucleation in complex multicomponent system
The continuing research and use of co-crystallisation for separation, purification and modification of pharmaceutical materials in multiple industrial sectors can be attributed to the potential for high control of product quality attributes. Nucleation is a key phenomenon in crystallisation that …
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Molecular simulation study of homogeneous crystal nucleation in n-alkane melts
… Monte Carlo (MC) method to study the homogeneous crystal nucleation in the melts of n-alkanes, the simplest class of chain molecules. Three n-alkanes with progressive chain length were studied, n-octane (C8), n-eicosane (C20), and C150, using a united atom force field, which is able to reproduce …
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Particle assisted protein crystal nucleation as a protein purification platform for pharmaceutical manufacturing
Slow protein crystal nucleation is a major barrier to using crystallization as a separation and purification strategy in protein drug manufacturing. This work investigates the use of functionalized nanoparticles in solution to act as in situ templates for initiating crystal nucleation. We used …
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An Investigation of Phase Behavior and Crystal Nucleation Kinetics in Solutions of Globular Proteins
Nucleation and growth of low defect density structures remains a significant technological challenge. Indeed, when dealing with nanoparticles with chemically heterogeneous surfaces, locating crystallizing conditions remains an art rather than a science. Particular examples of these problems can be …
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UNDERSTANDING AND EVALUATING CRYSTAL POLYMORPHISM BY SECOND HARMONIC GENERATION MICROSCOPY
The crystalline form of a solid can profoundly affect its physical and chemical properties, with both potentially stable and metastable crystal polymorphs are accessible during crystal formation. Conventional methods limit the detection of rare nucleation and rapid phase transitioning events due to …
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Coherent X -Ray Diffractive Imaging and Nucleation of Protein Crystals
… The preparation of high quality protein crystals suitable for structure determination often proves difficult and even impossible. The technique of coherent x-ray diffraction was used to try to gain a better understanding of protein crystal nucleation and growth. Results are presented …
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Investigation of the crystallisation inhibitory properties of albumin isolated from the urine of Black and White South Africans
… more potent inhibitors of calcium oxalate (CaOx) crystallisation in urine from blacks compared to those occurring in the urine of white subjects. Urinary proteins have been shown to be inhibitors. This study investigated the crystallisation inhibitory properties of albumin isolated from the urine …
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Analysis of nucleation kinetics in pH-shift crystallization using agitated and microfluidic systems
Crystal nucleation is a key event in the process of crystallization and is important in a number of processes in the pharmaceutical industry. Nucleation kinetics impact the crystal quality attributes of the product of a crystallization process. For example, increased crystal nucleationrate can lead …
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Elucidation of Protein -Precipitant Phase Diagrams and Their Link to Crystal Quality
… will be useful in obtaining high quality crystals for X-ray diffraction studies. Moreover, we use theory to compare different protein molecules on a generalized phase diagram using the solubility data obtained from our experiments. The comparison of the solubility boundary and the …
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OPTIMIZATION AND CHARACTERIZATION OF SELF-ASSEMBLED POLY(STYRENE-B-(3,4-ISOPRENE-STAT-1,2-ISOPRENE) BLOCK COPOLYMER THIN FILMS
… candidates as advanced templates for inorganic crystallization. Their periodic order, nanoscale spacing and precise control of surface chemistry in one block allow them to confine the crystal nucleation and growth both physically and chemically. In this work, a …
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Raman studies of the nanostructure of sol-gel materials
… Key material phases analyzed were: (1) nanocrystalline boehmite [AlO(OH)]; (2) bayerite, nordstrandite, and gibbsite [Al(OH)₃ polymorphs]; (3) amorphous zirconia [a-ZrO₂]; and (4) magnesite [MgCO₃], hydromagnesite [4MgCO₃·Mg(OH)₂·5H₂0], and magnesia [MgO]. Crystal nucleation and crystal …
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Oriented polymer crystal growth from flowing solutions
The kinetics of dilute solution flow-induced crystallization in a tubular flow geometry have been quantified for several polymer systems using digital image processing to observe and monitor the birefringence of the crystallizing fiber. Three molecular weights of polyethylene were studied in 0.01 …
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Direct energy landscape sampling of the homogeneous nucleation and crystal growth of a model liquid
… step in the synthesis of any material is the nucleation of the material's phase. Nucleation and crystal growth are understood to be activated processes involving the crossing of free-energy barriers. Attempts to capture the entire crystallization process over long timescales with molecular …
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Nonclassical Mechanisms to Inhibit β-Hematin Crystallization Illuminate the Cooperative Action of Antimalarials
… during hemoglobin digestion, into inert hemozoin crystals. Because disruption of this detoxification pathway is a major route of parasite killing, understanding how these crystals form and how drugs interfere with their formation is important for both fundamental mechanism and antimalarial …
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Solution History Effects and Crystal Phase Transformation in Polybutene-1 and Domain Morphology in Polyurethanes
Isotactic polybutene-1 (PB-1) can crystallize in four different crystal forms in which the molecules assume three different helical conformations. When PB-1 crystallizes from a dilute solution the crystal form which precipitates is determined by the thermal history imposed on the solution and the …
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The effect of inositol-hexakisphosphate (phytate) on urinary risk factors for calcium oxalate urolithiasis in South African population groups with different kidney stone risk profiles : theoretical modelling, in vitro crystallisation experiments and in vivo human studies
… complexes inhibit calcium oxalate crystallisation and whether a higher dietary intake of phytate in South African black subjects compared to white subjects may contribute to the relative rarity of urolithiasis in this group. Potentiometric titrations were conducted to determine …
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The superconducting properties, composition and microstructure of nanocrystalline $A15\ \textnormal{Nb}_{3}(\textnormal{Al}_{1-x}\textnormal{Ge}_{x})$ superconductors for high magnetic field applications
… and properties of state-of-the-art nanocrystalline $\textnormal{Nb}_{3}\textnormal{Al}_{1-x}\textnormal{Ge}_{x}$ superconductors with 0 ≤ x ≤ 1. High-energy ball milling was used to produce disordered nanocrystalline powders from binary compounds and from pure elemental powders. A …
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Investigation of the in vitro and in vivo effects of some herbal preparations on risk factors for calcium oxalate kidney stone disease
… effects of six plant extracts were tested on the crystallization characteristics of calcium oxalate (CaOx), the predominant stone-forming salt in urine. These investigations were performed in synthetic urine and real urine collected from healthy black and white South African males and the …
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