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Showing 1 to 20 of 28 for “"Beta phase"”.
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Mathematical Models of the Alpha-Beta Phase Transition of Quartz
… the sequence of transitions with the alpha-inc-beta phase transition of quartz. We examine a model by Parlinski which employs interactions of nearest and next-nearest neighbor atoms. We numerically determine the configurations which lead to minimum energy for a range of parameters. We then use …
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Photophysical Studies of Beta Phase Formation in Poly(9,9-di-n-alkylfluorenes)
… upon formation of the beta phase in methylcyclohexane solution are observed by optical spectroscopy. The equilibrium absorption spectra as a function of temperature show that conformational changes occur for all five polymers studied, from the hexyl (PF6) to decyl (PF10) …
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First Demonstration of beta-phase Gallium Oxide Optical Waveguide in Visible-UV Spectrum
We report the first demonstration of beta-phase gallium oxide (β-Ga2O3) as optical waveguides on sapphire substrates grown by metal-organic chemical vapor deposition (MOCVD). Their propagation losses in the visible spectrum were comprehensively studied via experiments and simulations of the finite …
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Study of the properties of hydrogen and deuterium in beta phase palladium hydride and deuteride
… high concentrations to form the well-established beta phase. Direct measurements of the tracer diffusion of these isotopes have been made for two sample geometries using quasielastic neutron scattering on Osiris at ISIS (Harwell, UK) and IN5 at The Institut Laue Langevin (Grenoble, France). …
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Self-Diffusion Studies in Beta-Phase Ordered Alloys of Gold - Cadmium by Radioactive Tracer Technique
Made available in DSpace on 2014-12-04T23:26:50Z (GMT). No. of bitstreams: 1 6200611.pdf: 2377480 bytes, checksum: ebe0725609c6fb3632e46f4ce5ba6b67 (MD5) Previous issue date: 1961
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High Temperature X-Ray Decomposition Studies of Alpha Phase Nickel-Silicon and Beta Phase Copper-Aluminum-Nickel Alloys
… which formation of an ordered (gamma)' Ni(,3)Si phase occurred by a continuous transformation, and above which precipitation occurred by nucleation and growth processes. The X-ray results, however, have shown that the precipitation is actually dependent upon the thermal history of the specimen. …
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X-Ray and Neutron Scattering Studies of Niobium-Hydrogen Alloys Near the Alpha-Prime to Beta Phase Transition
… < x < 0.85) in the vicinity of the (alpha)'-(beta) phase transition was conducted using x-ray and elastic neutron scattering techniques in the temperature range 300 < T < 473 K. Diffuse scattering close to the Bragg peaks of the BCC (alpha)' phase was measured. The temperature dependence of …
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Deformation Substructure and Slip Systems in Directionally Solidified Gamma-Phase Nickel(3)aluminum(1) - Beta-Phase Nickel(3)niobium(1) Eutectic Composite to 600 Degrees C
Made available in DSpace on 2014-12-14T16:00:33Z (GMT). No. of bitstreams: 1 7714929.pdf: 5377124 bytes, checksum: f9dcc2e42caf0948287263a737af8b2c (MD5) Previous issue date: 1977
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Electromagnetic response of time-reversal breaking metallic phases in two dimensions
We explore two phases in two-dimensional electron fluids in which the time-reversal symmetry is broken spontaneously by using the method of higher dimensional bosonization. Mean-field calculations show that the order parameter is two two-component real vectors [Sun and Fradkin 2008]. There are two …
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STM Study of 2D Metal Chalcogenides and Heterostructures
… The second part of the dissertation focuses on phase transformation in 2D In2Se3. We observed that 2D In2Se3 layers with thickness ranging from single to ~20 layers stabilized at the beta phase with a superstructure at room temperature. After cooling down to around 180 K, the beta phase …
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Aging Effects in Copper-Zinc-Aluminium Shape Memory Alloys (Martensite, Bainite)
Aging in both the beta phase and martensitic state of Cu-Zn-Al alloys causes deterioration and instability of shape memory properties, even at moderate temperatures. These aging effects have been studied by electrical resistivity measurements and bend tests. The corresponding changes in …
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An Electron Microscopy Study of Modulated Microstructures in Beta Nickel-Aluminum and Other Alloys
The tweed contrast in an as-quenched, beta phase 63% nickel-aluminum alloy has been studied by conventional transmission electron microscopy. Supplemental investigations have been carried out on the 3R, 7R, Ni(,5)Al(,3) and Ni(,3)Al phases in the same alloy in the as-quenched condition or after …
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The diffusion of Co⠶溩 Zrâ â Tiâ â alloy /|nS. Kumar. -- 260 St Catharines [Ont.] : Dept. of Physics, Brock University,
The diffusion of Co60 in the body centered cubic beta phase of a ZrSOTi SO alloy has been studied at 900°, 1200°, and 1440°C. The results confirm earlier unpublished data obtained by Kidson17 • The temperature dependence of the diffusion coefficient is unusual and suggests that at least two and …
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Effect of phase transformations, chemical doping, and matrix constraint on the microstructural development of dicalcium-silicate
The factors controlling the monoclinic ($\beta$) to orthorhombic ($\gamma$) transformation of dicalcium silicate (Ca$\sb2$SiO$\sb4$) at about 490$\sp\circ$C have been studied. This transformation is of interest in portland cement technology because the low temperature $\gamma$ phase is unreactive …
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Ion assisted magnetron sputtering of tantalum thin film deposition and characterization
… of ion bombardment on the crystallographic phases of tantalum films during their deposition by magnetron sputtering process, and to gain understanding of the mechanism of the ion-solid interactions during the thin film growth. Tantalum (Ta) exists in two distinct crystallographic phases: a …
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Caracterização do resíduo pós-industrial de PVDF visando potencial utilização via reciclagem primária
… in its microstructures coexistence of alfa end beta phase. The thermal aging was responsible for promoting thermo-oxidation in the samples which lead to secondary crystallization, however, this secondary crystallization did not affect significantly the materials thermal stability and mechanical …
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Nanotemplate creation and self-assembly on the (111) surface of gold
… and the formation of two new continuous ordered phases--an in-plane oriented stripe phase (beta-phase) and an out-of-plane pointing, close-packed phase (&phgr;-phase). These results complement recent theoretical investigations and contribute to an ongoing DFT study of the energetics of the …
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Interdiffusion Analysis For Nicocraly And Nial Vs. Various Superalloys
… the coatings degrade by composition and phase changes due to oxidation/hot-corrosion, and multicomponent interdiffusion from and into the superalloy substrate. In this study, the rate of Al interdiffusion into selected Ni-base superalloys using various diffusion couples of two-phase …
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Strengthening of metastable beta titanium alloys
… material behavior and properties. Metastable $\beta$ titanium alloys are a subset of titanium alloys with huge potential for the aerospace sector. However, they exhibit atomic transformations which, even after 60 years of research, are still disputed. For example, these alloys are strengthened …
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