despite the care taken to ensure the quality of date collected by enumeration and sampling, the final tabulation will sometimes give obvious indication of errors in basic information. evaluation of these errors furnishes those who use such a study and sampling. more general, the finding in these studies should be helpful to others that conduct surveys. in order to compare the age composition of...

supported catalysts synthesized via the interaction of mg(oet)2 with ticl4 in the presence or absence of an internal stereoregulating donor (di-n-butyl phthalate), with different solvents (chlorobenzene, n-undecane, n-heptane) at different titanation temperatures have been studied by a set of physicochemical methods. data on the chemical composition, x-ray structure and pore structure of these ...

composition and structure of a three-storied fagus orientalis-dominated forest was investigated in the caspian forests, north of iran. circular sampling plots of 1000 m2 occupied by advance growth and natural regeneration were randomly chosen where the initial cuttings (with shelterwood aim) were performed. abundance of species at different growth stages and quality of seedlings and saplings we...

objectives the overall goal of this study was to carry out a set of comparative analyses of arsr gene in plasmid r773 and bacterial chromosome from escherichia coli bl-21(de3). methods pdb and ncbi databases and chimera, mega4, clc main workbench software and 3d-jigsaw and embl-ebi servers were applied to perform this study. by using these software and servers, multiple analyses including deter...

Supported catalysts synthesized via the interaction of Mg(OEt)2 with TiCl4 in the presence or absence of an internal stereoregulating donor (di-n-butyl phthalate), with different solvents (chlorobenzene, n-undecane, n-heptane) at different titanation temperatures have been studied by a set of physicochemical methods. Data on the chemical composition, X-ray structure and pore structure of these ...

zno thin films were deposited on si(400) substrates by e-beam evaporation technique, and then post-annealed at different annealing temperatures (200-800°c). dependence of the crystallographic structure, nano-strain, chemical composition and surface physical morphology of these layers on annealing temperature were studied. the crystallographic structure of films was studied using x-ray diffracti...