Arylsulfatase was purified 219-fold from Pseudomonas sp. strain C12B. The final preparation was homogeneous by electrophoretic and immunological analysis. The enzyme is a monomer of molecular weight about 51,000, with a Stokes radius of 3.0 X 10(-7) cm, a frictional ratio of 1.2, and a sedimentation coefficient of 4.1S.

It is a convenient approximation to regard the frictional forces between two solids as made up of two components: the force required to shear adhering junctions in the region of surface contact and the force required to deform the underlying bulk material.' With an elastic solid, the deformation component may be due mainly to an elastic hysteresis loss; but if plastic flow occurs, the deformati...

inclined retaining walls with slopes less than perpendicular are appropriate candidates in several engineering problems. yet, to the knowledge of authors, only a few analytical solution for calculation of active earth pressure on such walls, which will be usually smaller than the same pressure on vertical ones, has been presented neither in research papers nor in design codes. considering limit...

Based on the assumption that fault slip dominates in stress relaxation brittle crust, Coulomb theory allows for crustal estimation with an empirical frictional coefficient. However, natural variability of friction and uncertainty exist Earth's crust. To address extent to which heterogeneous slips influence its evolution, we establish a quasi-static, 2D model represent fractured rock mass. The c...

[1] We discuss the impact of uncertainties in computed coseismic stress perturbations on the seismicity rate changes forecasted through a rateand state-dependent frictional model. We aim to understand how the variability of Coulomb stress changes affects the correlation between predicted and observed changes in the rate of earthquake production. We use the aftershock activity following the 1992...

Frictional interfaces lose stability via earthquake-like ruptures, which are close analogues of shear cracks that well-described by fracture mechanics. Interface however, need to be first formed—or nucleated. Rupture nucleation therefore determines the onset friction, replacing concept a characteristic “static friction coefficient”. Utilizing rupture arrest at an imposed barrier, we experimenta...

The aim of this study was to compare the static and kinetic frictional forces generated by various contemporary designs of self-ligating brackets (SLBs) and different wire alloys. In total, six different brackets (four passive type SLB, one active SLB, and one conventional bracket) were investigated using stainless steel, nickel-titanium, and titanium-molybdenum alloy archwires of several sizes...