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Showing 1 to 15 of 15 for “"Glass Formation"”.
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Glass formation and thermal history.
Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.
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On the application of machine-learning to the study of glass-formation in metallic systems: Prediction, optimisation, and characterisation of novel glassy alloys
Metallic glasses (MGs) are amorphous materials created by quenching a molten alloy mixture so quickly that crystalline phases do not have time to nucleate and grow, leaving a solid material with liquid-like structural disorder. This lack of crystalline ordering in MGs gives rise to a variety of …
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Towards Glasses from Two-Dimensional Hybrid Organic–Inorganic Perovskites
… melt, and be quenched into frozen liquids, i.e., glasses, opening up new avenues for disordered perovskite materials. Despite the growing number of glass-forming HOIPs, fundamental understanding of their vitrification processes remains limited. This thesis focuses on a prototypical two-dimensional …
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Aspects of amidization of chitosan
… ¹³C NMR, and HPLC were used to study the transformation of various ionic complexes of chitosan (N-acylate) to their respective N-acyl homologs of chitosan; and several properties of these materials were examined. DMTA and TMA provided information on changes in T<sub>g</sub> as well as …
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Physical Aging of Miscible Polymer Blends
… measurements were performed on various polymeric glasses with the overriding goal of developing a better molecular picture of the nonequilibrium glassy state. To this end, aging-induced changes in mechanical properties and in the thermodynamic state (volume and enthalpy) were assessed for two …
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Phase equilibria in iron phosphate system
… in the iron phosphate system, focusing on the glass forming area, and investigate glass formability and properties based on the liquidus regions. Twelve iron phosphate compounds were successfully prepared and studied in terms of liquidus temperature or decomposition behavior. The liquidus …
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Evaluation of environmental materials as thermal witness materials
… and undergo a quantifiable physical change/transformation. The extent of change is determined post exposure and a correlation is made between the extent of observed change and the exposed time-temperature profile. The thermosensors under investigation, Jarosite and silicate glass are materials …
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Purely ionic and molecular orbital modelings of the bonding in mineral crystal structures
… or polyphosphates to polymorphism or glass formation. Other properties of H₂SO₄ are also calculated and compared with experimental observations and previous calculations.
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Development of multi-component iron-based amorphous alloy
… system which is capable of forming a metallic glass on rapid solidification of the melt, rather than modifying a known glass forming composition, and assessing its glass forming ability. Iron (Fe) was chosen as the solvent element because it is significantly cheaper than the base elements found …
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High Entropy Amorphous and Crystalline Li-Garnet Films for Lithionic Applications
… Li+-conductive oxides. These high-entropy glass-ceramic phases consist of the highest number of local building units (LBUs) ≥ 4 being identified so far with edge- and face-shared LBUs, not conforming to the traditional Zachariasen glass formation rules. Within the aLLZO structure, we …
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Thermophysical and Structural Measurements of Liquid Metallic Alloys Using Electrostatic Levitation
<p>In the study of the glass transition, the properties of high temperature liquids in their equilibrium and supercooled states may provide clues to the question of why certain compositions form glasses more easily than others. In metallic alloys such measurements are difficult due to the high …
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Design and development of drug delivery systems for immediate and sustained release utilizing hot melt extrusion
… in solid dispersions, since it is known that glass formation is comin many polyhydroxy substances, presumably due to their strong hydrogen bonding which may prevent re-crystallization of the amorphous form of drug molecules. Furthermore, they possess the advantage of high thermal stability and …
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Thermomechanical Processing of Metallic Glasses
… on its thermal and kinetic history, a metallic glass (MG) of a given composition can show a wide range of energetic states. One central parameter determining the initial state of a glass is the cooling rate used to form it upon quenching from the melt. A faster cooling rate will give rise to a …
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High thermal expansion phosphorus oxide and oxynitride glasses
<p>"The chemical durability of phosphate glasses in general can be improved by the incorporation of chemically dissolved nitrogen and/or addition of oxides such AI<sub>2</sub>O<sub>3</sub>.</p> <p>Over 100 oxide and oxynitride glass compositions were evaluated. The general compositions investigated …