the aim of this paper is to minimize output phase noise for the pure signal synthesis in the frequency synthesizers. for this purpose, first, an exact mathematical model of phase locked loop (pll) based frequency synthesizer is described and analyzed. then, an exact closed-form formula in terms of synthesizer bandwidth and total output phase noise is extracted. based on this formula, the phase ...

in the present research, in contrast to the available papers, not only the superelasticity but also the shape memory effects are taken into account in determination of the impact responses. at the same time, in addition to modifying brinson’s model for the shape memory alloys (smas), to include new parameters and loading events, and hertz contact law, distributions of the sma phases are conside...

Urban centres in the world are undergoing facets of changes, these changes are evident in developing countries and more divergent because urban transformation in developing countries is often accompanied challenges which include traffic congestion, overcrowding, pollution and continuous land use succession. This phenomenon is not different with the central area of Minna, Nigeria. Since 2008 the...

The conventional wisdom to tailor the properties of binary transition metal carbides by order-disorder phase transformation has been inapplicable for the machinable ternary carbides (MTCs) due to the absence of ordered phase in bulk sample. Here, the presence of an ordered phase with structural carbon vacancies in Nb4AlC3-x (x ≈ 0.3) ternary carbide is predicted by first-principles calculations...

Successful theories of phase transformation processes include classical nucleation theory, which envisions a local equilibrium between coexisting phases, and nonequilibrium kinetic cluster theories. Using computer simulations of the magnetization reversal of the Ising model in three different ensembles we make quantitative connections between these physical pictures. We show that the critical n...

in this research, a sol gel autocaombustion route has been proposedto synthesize alumina-zirconia composite powders, usingammonium bicarbonate as a new fuel. then the effect of calcinationtemperature on phase transformation and crystallite sizes wasinvestigated. to characterize the products xrd, tem and betanalyses were used. xrd patterns of as-synthesized powder andcalcined powders at 1100 ◦c ...