Silica nanoparticles (SNPs) are widely used all around the world and it is necessary to evaluate appropriate risk management measures. An initial step in this process is to assess worker exposures in their current situation. The objective of this study was to compare concentrations and morphologic characteristics of fumed (FS) and sol-gel silica nanoparticles (SS) in two manufacturing facilitie...

It is well-known that the second smallest eigenvalue 22 of the difference Laplacian matrix of a graph G is related to the expansion properties of G. A more detailed analysis of this relation is given. Upper and lower bounds on the diameter and the mean distance in G in terms of 22 are derived.

seventeen iranian shallot genotypes from ashtian, arak, boroujerd, dashtearjan, doshmanziari, divandareh, khomein, khansar, sepidan, siakhdarengoon, sahne, kangavar, koohrang, koohmaresorkhi, nahavand, harsin and yasouj areas were evaluated for their morphological traits. corms were collected from the mentioned regions and planted based on a complete block design. quantitative and qualitative t...