the preparation of nano-sized tio2 by titanium tetraisopropoxide (ti(oipr)4) via sol-gelmethod using acid as a catalyst is investigated and the optimized conditions concerning theproportional amount of acid, water, alcohol is established by xrd and sem. the effect ofcalcination temperature on phase transformation of tio2 (rutile, anatase and brookite) wasdetermined by xrd. the smallest grain si...

An account is presented on investigation of the effects of synthesis parameters, i.e., reaction sources, silica to alumina ratio, acid molar ratio and crystallization conditions on the crystallinity, morphology and particle size of SAPO-34. The synthesis conditions were designed to produce small particles with narrow size range. The prepared samples were characterized by XRD and SE...

A digital decision-directed phase-locked loop (PLL) for use in optical pulse code-division multiple-access (CDMA) systems based on coherent correlation demodulation is proposed. PLL performance is affected by multiuser interference, laser phase noise and optical shot noise. The effect of these sources of interference and noise on PLL performance is evaluated based on a nonlinear model (the Fokk...

The aim of this study was to investigate the sol gel synthesis of HA/FA nanoparticles and the possible formation of TCP phase or unstoichiometric calcium deficient hydroxyapatite (CDHA) from the precursors with a Ca/P ratio of 1.62. In order to prepare the sol, the solutions of Triethyl phosphite, ammonium fluoride and calcium nitrate in ethanol were used respectively as P, F and Ca precursors....

In this research, the Planetary mill was used for mechanical alloying (MA) of Ti and Alpowder mixture with equal at% (Ti50Al50). The effect of various factors, such as process control agent(PCA), speed of rotation of vial and ball-to-powder weight ratio, on process were studied and the bestcondition to synthesis the alloy was determined. Study on X-ray diffraction (XRD) patterns showedthat at p...

The solvent extraction of gallium from a concentrated Jajarm Bayer process liquor containing 164.90 g/l of Na2O, 86.70 g/l of Al2O3 and 106.02 ppm of gallium was investigated using 10 vol.% Kelex100, a 7-alkyl substituted-8 hydroxyquinoline as an extractant, 10 vol.% etanol as a modifier and kerosene as a diluent. At (Vo :Va = 1.0:1.0) ...

In a classical PLL, the phase detector (PD) and charge pump (CP) noise is multiplied by N, when referred to the VCO output, due to the divide-by-N in the feedback path. It often dominates the in-band phase noise and limits the achievable PLL jitter•power Figure-Of-Merit (FOM). A sub-sampling PLL uses a PD that sub-samples the high frequency VCO output with the reference clock. The PD and CP noi...

The aim of this study was to investigate the sol gel synthesis of HA/FA nanoparticles and the possible formation of TCP phase or unstoichiometric calcium deficient hydroxyapatite (CDHA) from the precursors with a Ca/P ratio of 1.62. In order to prepare the sol, the solutions of Triethyl phosphite, ammonium fluoride and calcium nitrate in ethanol were used respectively as P, F and Ca precursors....