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 this study, direct laboratory measurements of unsteady-state imbibition test are used in a new approach to obtain relative permeability curves with no predetermined functionality assumptions. Four equations of continuity, Darcy’s law, cumulative oil production, and water fractional flow are employed in combination together under certain assumptions to present the new approach which interpret...

Background: Chronic low back pain (CLBP) disability has been particularly frustrating because its treatment has been a great therapeutic challenge. Disability has been suggested to depend on different factors that should be found and considered in the medical management. The inter-segmental coordination is often impaired in CLBP subjects; however, to the best of our knowledge, there is no evide...

In this study, a chemical additive made by a combination of polymer, alkaline, and silica nanoparticles is used to control the oil recovery and relative permeability curves. Various parametersincluding the type and concentration of polymer, alkaline, and nanosilica particles have been studied.To evaluate the efficiency of these additives, we performed unsteady state displaceme...

infection process including spore germination, penetration and intercellular development of cercospora beticola in the mesophyll of immature and mature leaves of two resistant  (fd0018 and hm1836) and a susceptible genotypes (236) of sugar beet were studied, in order to determine the relative importance of defense phenomena in pre and post-penetration stage of infection to the pathogen in sugar...

a solid-phase extraction (spe) method for sample clean-up and preconcentration followed by reversed-phase high-performance liquid chromatography (rp-hplc) with uv detection is reported for determination of polycyclic aromatic hydrocarbons (pahs) in the caspian seawater. a good resolution was obtained using acetonitrile:water (40:60) as mobile-phase for separation of these compounds. the effect ...

the principle of equality of arms means that each party in an action shall present her claim in an environment so that this does not put him in a worse condition compared to the other party of the trial. this principle has been internationally and locally embraced by authorities. from the perspective of international documents, the acceptance of this principle is partly influenced by the accept...

We propose and experimentally demonstrate that the intensity noise correlation and the noise level of intensity-difference and intensity-sum in Stokes and anti-Stokes channel can be well controlled by the relative nonlinear phase in spontaneous parametric four-wave mixing process. By modulating the relative nonlinear phase, including self-phase modulation and cross-phase modulation, switching t...

A reversed-phase salt assisted liquid-liquid extraction (RP-SALLE) method was developed for the preconcentration and determination of trace crocin in herbal medicines by high-performance liquid chromatography (HPLC). In developed method, the roles of the aqueous and organic phases are inverted so that the analyte is extracted from the organic into the aqueous phase after salt addition and phase...