the history of mankind is intertwined with war. what distinguishes man from other creatures is his ability to dominate and capture the nature; he accomplishes this though using his rationale and making tools which set the ground for production and accumulation of capital. to protect his benefits and accomplish his desire for dominance, man creates weapons which become more developed parallel to...

We answer the following question: Let λ, μ, ν be arbitrary real numbers. Does there exist a 3-dimensional homogeneous Riemannian manifold whose eigenvalues of the Ricci tensor are just λ, μ and ν ? It is essential to observe that inspite of the fact that the curvature of a 3–manifold is uniquely determined by the Ricci tensor, nevertheless, the constancy of all its three eigenvalues does not im...

introduction: preparation techniques and instruments produce and push debris out of canals. this can induce inflammation within the periapical area. therefore, instrumentation that causes less extrusion of debris is more desirable. the purpose of this in vitro study was to evaluate the quantity of debris extruded from the apical foramen during root canal preparation by using one hand, and two r...