Objective The Holmium:yttrium-aluminum-garnet (Ho:YAG) laser is the standard lithotrite for ureteroscopy. This paper is to evaluate a Ho:YAG laser with a novel effect function in vitro, which allows a real-time variation of pulse duration and pulse peak power. Methods Two types of phantom calculi with four degrees of hardness were made for fragmentation and retropulsion experiments. Fragmenta...

The brittle fracture of a gypsum cylinder, which is used as an artificial kidney stone in lithotripsy research, is simulated by the use of the finite element method. The cylinder is submerged in water and is subjected to a pressure front parallel to one of its planar faces. The stresses induced by the pressure wave lead to fracture in the interior of the cylinder, with the formation of a spall ...

Several technical difficulties diminish the usefulness of serum triglyceride estimation by the method of Stone and Thorp [C/in. Chim. Acta 14, 812 (1966)]. An artificial and somewhat unstable material is used in the standardization. Falsely elevated readings caused by scratched cuvettes are a frequent problem. Conventional quality-control procedures cannot be used because stable preparations ar...

A conservative invariant domain preserving Arbitrary Lagrangian Eulerian method for solving nonlinear hyperbolic systems is introduced. The method is explicit in time, works with continuous finite elements and is first-order accurate in space. One originality of the present work is that the artificial viscosity is unambiguously defined irrespective of the mesh geometry/anisotropy and does not d...

We analyze a well known type of puzzle in planar geometry: given a planar shape, it is required to find a cut that divides the shape into two identical parts (up to rotation and translation). Clearly not all shapes can be so dissected and for some shapes that appear in puzzles the cutting curve is quite surprising and difficult to find. In this paper we first analyze the inverse problem of asse...

The development of artificial stone from the agglutination polymeric resin using industrial wastes can be a viable alternative technical, economic, and sustainable point view. main objective present work was to evaluate physical, mechanical, structural properties stones based on quartzite waste added into synthetic, epoxy, or biodegradable polyurethane polymer matrix. Artificial plates were pro...

Brazil is one of the world’s major ornamental stone producers. As a consequence, wastes are generated on large scale and usually open air disposed. Thus, it important to develop novel material reusing these accumulated wastes, aiming minimize environmental impact. The development artificial stones made with agglomerated by synthetic polymer represents an excellent alternative and, therefore, cu...