scholarly journals Synthesis of Metastable or Non-Equilibrium Phased Oxides and Their Physical Properties

2019 ◽  
Vol 68 (10) ◽  
pp. 733-738
Author(s):  
Kentaro KANEKO ◽  
Shizuo FUJITA
2019 ◽  
Vol 66 ◽  
pp. 42-60 ◽  
Author(s):  
M. Hantke ◽  
S. Müller

A class of non-equilibrium models for compressible multi-component uids is investigated. These models are subject to the choice of interfacial pressures and interfacial velocity as well as relaxation terms for velocity, pressure and chemical potentials. Sufficient conditions are derived for these quantities that ensure meaningful physical properties such as a non-negative entropy production and thermodynamical stability as well as mathematical properties such as hyperbolicity. For the relaxation of chemical potentials a three-component model gas-water-vapor is considered.


Author(s):  
Yu Shi ◽  
Daoyong Yang

A novel and pragmatic technique has been proposed to quantify the non-equilibrium phase behaviour together with physical properties of foamy oil under reservoir conditions. Experimentally, constant-composition expansion (CCE) experiments at various constant pressure decline rates are conducted to examine the non-equilibrium phase behaviour of solvent-CO2-heavy oil systems. Theoretically, the amount of evolved gas is firstly formulated as a function of time, and then incorporated into the real gas equation to quantify the non-equilibrium phase behaviour of the aforementioned systems. Meanwhile, theoretical models have been developed to determine the time-dependent compressibility and density of foamy oil. Good agreements between the experimentally measured volume-pressure profiles and calculated ones have been achieved, while both amounts of evolved gas and entrained gas as well as compressibility and density of foamy oil were determined. The time-dependent effects of entrained gas on physical properties of oleic phase were quantitatively analyzed and evaluated. A larger pressure decline rate and a lower temperature are found to result in a lower pseudo-bubblepoint pressure and a higher expansion rate of the evolved gas volume in the solvent-CO2-heavy oil systems. Apparent critical supersaturation pressure increases with either an increase in pressure decline rate or a decrease in system temperature. Physical properties of the oleic phase under non-equilibrium conditions follow the same trends as those of conventionally undersaturated oil under equilibrium conditions when pressure is higher than the pseudo-bubblepoint pressure. However, there is an abrupt increase of compressibility and decrease of density associated with pseudo-bubblepoint pressure instead of bubblepoint pressure due to the initialization of gas bubble growth. The amount of dispersed gas in the oleic phase is found to impose a dominant impact on physical properties of the foamy oil. Compared with CCE experiment at constant volume expansion rate, a rebound pressure and its corresponding effects on physical properties cannot be observed in the CCE experiments at constant pressure decline rate.


1976 ◽  
Vol 32 ◽  
pp. 365-377 ◽  
Author(s):  
B. Hauck
Keyword(s):  

The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical properties for the Ap stars, or of detecting new ones. My talk today is prepared in this spirit. The classification by means of photoelectric photometric systems is at the present time very well established for many systems, such as UBV, uvbyβ, Vilnius, Geneva and DDO systems. Details and methods of classification can be found in Golay (1974) or in the proceedings of the Albany Colloquium edited by Philip and Hayes (1975).


Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.


Author(s):  
K.P.D. Lagerlof

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.


Author(s):  
Edward A Kenik

Segregation of solute atoms to grain boundaries, dislocations, and other extended defects can occur under thermal equilibrium or non-equilibrium conditions, such as quenching, irradiation, or precipitation. Generally, equilibrium segregation is narrow (near monolayer coverage at planar defects), whereas non-equilibrium segregation exhibits profiles of larger spatial extent, associated with diffusion of point defects or solute atoms. Analytical electron microscopy provides tools both to measure the segregation and to characterize the defect at which the segregation occurs. This is especially true of instruments that can achieve fine (<2 nm width), high current probes and as such, provide high spatial resolution analysis and characterization capability. Analysis was performed in a Philips EM400T/FEG operated in the scanning transmission mode with a probe diameter of <2 nm (FWTM). The instrument is equipped with EDAX 9100/70 energy dispersive X-ray spectrometry (EDXS) and Gatan 666 parallel detection electron energy loss spectrometry (PEELS) systems. A double-tilt, liquid-nitrogen-cooled specimen holder was employed for microanalysis in order to minimize contamination under the focussed spot.


Author(s):  
Michel Le Bellac ◽  
Fabrice Mortessagne ◽  
G. George Batrouni

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