The effect of pre-impact waves on the coefficient restitution (COR) in longitudinal impact a uniform elastic rod linear or bilinear inelastic spring supported by fix rigid wall is studied. models may represent quasi-static response of, e.g., small cylinder bit-rock interaction percussive drilling. accelerated to its momentum either force relatively short duration which generates significant (pr...

this study proposes a new linear approximation for solving the dynamic response equations of a rocking rigid block. linearization assumptions which have already been used by hounser and other researchers cannot be valid for all rocking blocks with various slenderness ratios and dimensions; hence, developing new methods which can result in better approximation of governing equations while keepin...

this study proposes a new linear approximation for solving the dynamic response equations of a rocking rigid block. linearization assumptions which have already been used by hounser and other researchers cannot be valid for all rocking blocks with various slenderness ratios and dimensions; hence, developing new methods which can result in better approximation of governing equations while keepin...

This article brings distinct strands of the political economy of communication and economic geography together in order to theorise the role digital technologies play in Marxian crisis theory. Capitalist advances into digital spaces do not make the law of value obsolete, but these spaces do offer new methods for displacing overaccumulated capital, increasing consumption, or accumulating new, ch...

When using existing ACL2 datatype frameworks, many theorems require type hypotheses. These hypotheses slow down the theorem prover, are tedious to write, and are easy to forget. We describe a principled approach to types that provides strong type safety and execution efficiency while avoiding type hypotheses, and we present a library that automates this approach. Using this approach, types help...

We describe a technique for arthroscopic anterior cruciate ligament (ACL) reconstruction using the middle third of the quadriceps tendon without a patellar bone block and absorbable tibial and femoral cross-pin fixation. The central part of the quadriceps tendon is harvested through a 5-cm long anterior skin incision without a patellar bone block. Tibial and femoral tunnels are prepared, the gr...

We consider a nonstandard D = 2 + 1 gravity described by a translational Chern–Simons action, and couple it to the nonrelativistic point particles. We fix the asymptotic coordinate transformations in such a way that the space part of the metric becomes asymptotically Euclidean. The residual symmetries are (local in time) translations and rigid rotations. The phase space Hamiltonian H describing...

We provide necessary and sufficient conditions for admissible transformations in the projectivised dual quaternion model of rigid body displacements and we characterise constraint varieties of dyads with revolute and prismatic joints in this model. Projective transformations induced by coordinate changes in moving and/or fixed frame fix the quadrics of a pencil and preserve the two families of ...