In this paper we examine the relations that may exist between the geometric variables most frequently used to describe left ventricular contraction. The left ventricle is represented by a thick-walled cylinder contracting both radially and longitudinally. For this model, wall thickening, mid-wall radius shortening and longitudinal axis shorteining can be shown to be uniquely related during cont...

Introduction. Cylindrical and spherical shells are extensively used in engineering. They face internal and/or external pressure heat. Stresses strains distribution elastoplastic has been studied by many scientists. Numerous works involve the use of von Mises yield conditions, maximum shear stress, reduced stress. These condi- tions do not include dependence on first invariant stress tensor sign...

4-Quinolones are the structural elements of many pharmaceutically active compounds. Although several approaches known for their synthesis, introduction an aryl ring in position 2 is problematic with most them. The reductive cyclization o-nitrochalcones by pressurized CO, catalyzed ruthenium or palladium complexes, has been previously reported to be a viable synthetic strategy this aim, but need...