introduction: the purpose of this study was to evaluate and compare canal preparation pattern of k3 and protaper rotary files in curved resin blocks. materials and methods: twenty-four resin blocks were used in this experimental study and randomly divided into two groups. their initial images were scanned. after preparation, their images were scanned again in the same position. pre and post pre...

Escherichia coli lipoproteins are anchored to the inner or outer membrane depending on the residue at position 2. Aspartate at this position makes lipoproteins specific to the inner membrane, whereas other residues cause the release of lipoproteins from the inner membrane in a manner dependent on both ATP binding cassette (ABC) transporter LolCDE and molecular chaperone LolA, followed by LolB-d...

The entropy generation analysis of non-Newtonian fluid in rotational flow between two concentric cylinders is examined when the outer cylinder is fixed and the inner cylinder is revolved with a constant angular speed. The viscosity of non-Newtonian fluid is considered at the same time interdependent on temperature and shear rate. The Nahme law and Carreau equation are used to modeling dependenc...

Introduction: Cigarette smoking has been recognized to be a risk factor for progression of periodontal disease . Due to less inflammation and bleeding in the presence of clinical signs of periodontal disease in smokers than in nonsmokers and given the conflicting results of studies on changes in the epithelium and gingival connective tissue by smoking, this study was performed to evaluate the t...

In this paper, a study on the vibration of thin cylindrical shells made of a functionally gradient material (FGM) composed of stainless steel and nickel is presented. The effects of the FGM configuration are taken into account by studying the frequencies of two FG cylindrical shells. Type I FG cylindrical shell has nickel on its inner surface and stainless steel on its outer surface and Type II...

the formation of charge-transfer complexation between dibenzo-15-crown-5 (db15c5) and benzo-12-crown-4 (b12c4) (donor) and iodine is investigated spectrophotometrically in three chlorinated solvents,chloroform, dichloromethane (dcm) and 1,2-dichloroethane (dce) solution at 25°c. the change in polarityof the solvent also doesn’t affect the stoichiometry of the complexes. values of formation cons...