Existence Of Multiple Phases Research Articles

Layer spacing gradient (NaLi)1−xCoO2 for electrochemical Li extraction

Layer spacing gradient (NaLi)1−xCoO2 for electrochemical Li extraction

AdS4 dyonic black holes in gravity's rainbow

In this paper, we investigate thermodynamical structure of dyonic black holes in the presence of gravity's rainbow. We confirm that for super magnetized and highly pressurized scenarios, the number of black holes' phases is reduced to a single phase. In addition, due to specific coupling of rainbow functions, it is possible to track the effects of temporal and spatial parts of our setup on thermodynamical quantities/behaviors including equilibrium point, existence of multiple phases, possible phase transitions and conditions for having a uniform stable structure.

THERMALLY-DRIVEN STRUCTURAL CHANGES OF SPUTTERED COPPER ALUMINUM OXIDE FILMS (Cu–Al2O3) GROWN BY LAYER STACKING METHOD

Copper aluminium oxide (Cu–Al2O3) films were synthesized on Si(111) substrates through RF magnetron sputtering by using the layer stacking technique. Cu and Al2O3 targets were used to deposit Cu and Al2O3 thin films under Ar atmosphere, respectively and the deposited films were then annealed under N2 environment at 350[Formula: see text]C, 450[Formula: see text]C and 550[Formula: see text]C for 6[Formula: see text]h. The structural properties of the films were investigated by using X-ray diffraction (XRD) while the surface morphology and topography of the deposited films were examined through Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX) and Atomic Force Microscopy (AFM). XRD analysis revealed the existence of multiple phases of CuO, Al2O3 and CuAl2O4 in the deposited films on Si(111) substrates. As a result of the annealing effect, the peak intensities of CuO, Al2O3 and CuAl2O4 were found to be increased along with the shifting of peak positions. Williamson–Hall (WH) analysis was also implemented to analyze the structural properties such as crystallite size, stress, strain, and energy density. Based on the three models used in WH analysis, the changes in the crystallite size and strain of the films were indicated to be anomalous with the changes in the annealing temperature. Moreover, the strain of films was also showed to be changed from compressive strain into tensile strain. The FESEM results also indicated the formation of various surface morphologies under various annealing temperatures whereas EDX analysis showed an increased atomic percentage of Cu, Al, and O due to the effect of increase in annealing temperature. The AFM analysis showed that the surface roughness of the deposited films increased with the increase in the annealing temperature.

Catalysis in Multifunctional Reactors

A multifunctional reactor is broadly defined as a multifaceted reactor system that combines a conventional reactor with any physical process to enhance the overall performance of the process to bring cost-effectiveness and/or compactness to a chemical plant. This multi-functionality can exist either on micro (catalyst) level or on macro (reactor) level [1]. There is substantial information available on several ways to achieve this task. Combining reaction with separation is one such popular approach. Here, when separation is performed in situ, several benefits like an increase in per-pass conversion and/or selectivity, energy integration, longer catalyst life, etc. are attained. When a separation process – e.g. distillation, adsorption, etc. – is to be performed simultaneously with a reaction, it imposes more restrictions on the reactor design so as to meet possible conflicting requirements that result from the reaction and separation. The existence of multiple phases as well as problems associated with heat and momentum transfer, mixing issues, etc. make the process complex, thereby attracting the attention of experts in reaction engineering, catalysis, modeling and simulation, and process design. Since catalysts are an integral part of a reactor system, many efforts have been made to manipulate its design to meet the above-mentioned challenges. A few examples are inserting special catalyst-filled envelopes into a distillation column to reduce pressure drop, manipulating the hydrophobicity of ion exchange resin in reactive chromatography for selective separation, grafting the catalyst in membrane material, etc. In this chapter, we review the recent literature on catalysts and their modified forms used in multifunctional reactors that combine reaction and separation. We restrict ourselves to the four most studied multifunctional reactors: reactive distillation, reactive stripping, membrane reactors and chromatographic reactors.

Influence of Ti–Si cathode grain size on the cathodic arc process and resulting Ti–Si–N coatings

The influence of the Ti–Si cathode grain size on cathodic arc processes and resulting Ti–Si–N coating synthesis has been studied. 63mm Ti–Si cathodes containing 20–25at.% Si with four dedicated grain size of ~8μm, ~20μm, ~110μm, and ~600μm were fabricated via spark plasma sintering or hot isostatic pressing. They were evaporated in 2Pa nitrogen atmosphere in an industrial-scale arc deposition system and the Ti–Si–N coatings were grown at 50A, 70A, and 90A arc currents. The composition and microstructure of the virgin and worn cathode surfaces as well as the resulting coatings were characterized using optical and electron microscopy, X-ray diffraction, elastic recoil detection analysis, X-ray photoelectron spectroscopy, and nanoindentation. The results show that the existence of multiple phases with different work function values directly influences the cathode spot ignition behavior and also the arc movement and appearance. Specifically, there is a preferential erosion of the Ti5Si3-phase grains. By increasing the grain size of the virgin cathode, the preferential erosion is enhanced, such that the cathode surface morphology roughens substantially after 600Ah arc discharging. The deposition rate of the Ti–Si–N coating is increased with decreasing grain size of the evaporated Ti–Si cathodes. The droplet number density and the droplet shape of the coatings are influenced by the arc movement, which is also shown to depend on the cathode grain size.

PHASE TRANSITIONS AND QUANTUM EFFECTS IN ANHARMONIC CRYSTALS

The most important recent results in the theory of phase transitions and quantum effects in quantum anharmonic crystals are presented and discussed. In particular, necessary and sufficient conditions for a phase transition to occur at some temperature are given in the form of simple inequalities involving the interaction strength and the parameters describing a single oscillator. The main characteristic feature of the theory is that both mentioned phenomena are described in one and the same setting, in which thermodynamic phases of the model appear as probability measures on path spaces. Then the possibility of a phase transition to occur is related to the existence of multiple phases at the same values of the relevant parameters. Other definitions of phase transitions, based on the nondifferentiability of the free energy density and on the appearance of ordering, are also discussed.

Formation of multiphased mixed crystals from miscible NaBr, KBr and KCl

AbstractMultiphased ternary and quaternary mixed crystals were grown by the melt method, for the first time, using the miscible alkali halides, viz. NaBr, KBr and KCl. X‐ray powder diffraction measurements indicate the existence of multiple phases. Density and refractive index were measured and the composition was determined. The metal atom contents determined through flame photometric measurements confirm the estimated composition of the crystals grown. The present study indicates the possibility of preparing multiphased ternary and quaternary mixed alkali halide crystals using the miscible NaBr, KBr and KCl as the starting materials. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

On the Preparation of Multiphased Mixed Crystals from NaBr and KCl

Multiphased mixed crystals were grown by the melt method, for the first time, using the miscible alkali halides, namely, NaBr and KCl. X-ray powder diffraction measurements indicate the existence of multiple phases and mostly of ternary mixed alkali halides. Density and refractive index were measured and the composition was determined. Results are reported.

New structure in the energy spectrum of reggeon quantum mechanics with quartic couplings

We find general that the energy spectrum of the reggeon hamiltonian with cubic plus quartic interactions at D=0 is more complicated than previously assumed. We observe the phenomenon of “ground state oscillation”, which suggests, for D ≠ 0, the existence of multiple phases. We find that for certain values of the parameters of the theory complex energy eigenvalues occur. We also find complicated level crossings among higher eigenvalues as the quartic coupling strength is increased.