We present a computer simulation study of the crystalline phases of hard ellipsoids of revolution. A previous study [P. Pfleiderer and T. Schilling, Phys. Rev. E 75, 020402 (2007)]. showed that for aspect ratios a/b>or=3 the previously suggested stretched-fcc phase [D. Frenkel and B. Mulder, Mol. Phys. 55, 1171 (1985)] is unstable with respect to a simple monoclinic phase with two ellipsoids of...

a sensitive and selective solid phase extraction procedure for the determination of traces of cd(ii),zn(ii) and ag(i) ions has been developed. an alumina-sodium dodecyl sulfate (sds) coated on with2,3 di hydro 2,3 para tolyl qinazoline (1 h)- 4 one (dptqo). the influences of the analyticalparameters including ph and sample volume were investigated. common coexisting ions did notinterfere on the...

a combined gas chromatography–mass spectrometry (gc–ms) with headspace solid-phase microextraction (hs-spme) method has been employed for the analysis of the flavor volatiles of some iranian rice cultivars (domsiah, deylamani, hashemi, shirodi and tarom). the samples were grown in different cities of mazandaran province. the sampling procedure and chromatographic conditions were same for all sa...

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 ...

in this work, the strontium-doped lanthanum manganite- a ceramic material- used as cathode in solid oxide fuel cells. an impression of grinding time on the structural and thermal properties of sr-doped lamno3 system with la1-xsrxmno3 (x=0.2) stoichiometric ratio was investigated. the nano crystallite lsm powder with cubic structure was prepared by varying the milling time of planetary monomill ...

a facile and highly efficient method have been developed for the preconcentration of the mercury content in crude oil and gasoline samples after digestion with microwave-assisted digestion. octadecyl silica membrane disk has been modified by the recently synthesized triazene ligand, (e)-1-(2-ethoxyphenyl)-3-(4-nitrophenyl) triaz-1-ene (ent), then the modified membrane was used for the preconcen...

a solid phase extraction sorbent based on polyaniline/graphene nanocomposite is presented. the structure and morphology of synthesized nanocomposite were investigated by fourier transform infrared spectroscopy, field emission scanning electron microscopy, x-ray diffraction and thermal gravimetric analysis. the dispersive solid phase extraction was employed to the isolation and preconcentration ...