Scour is one of the main causes hydraulic structural failures. The present experimental study examines use riprap, submerged vanes, and a combination these for scour reduction around vertical walls spill-through abutments under clear-water conditions. Specifically, influence placing riprap stones with different apron shapes (geometry) and/or group vanes constant height length on abutment was ex...

An in vitro study was conducted to determine the adaptation of composite resin restorative material to rounded and acute-angled retention grooves of Class I cavity preparations on 24 extracted premolars. Two chemically cured (P-IO ® and Miradapt ®) and 2 light-cured (Prisma-Fil ® and FulFil ®) composite resin materials, after being coded to create a blind study, were injected into cavity prepar...

Little is known about the cognitive demands that underlie surgical performance. Several studies have suggested that spatial ability plays a substantial role in surgical skill. An example of a skill in which spatial cognition appears to be of importance is the use of the angled laparoscope. This paper describes a virtual environment designed to assess and train the use of the angled laparoscope....

We prove that finitely generated purely loxodromic subgroups of a right-angled Artin group A(Γ) fulfill equivalent conditions that parallel characterizations of convex cocompactness in mapping class groups Mod(S). In particular, such subgroups are quasiconvex in A(Γ). In addition, we identify a milder condition for a finitely generated subgroup of A(Γ) that guarantees it is free, undistorted, a...

This paper describes a recognition mechanism based on the relationships between interest points and their properties that is applied to the problem of modelling the Poggendorff illusion. The recognition mechanism is shown to perform in the same manner as human vision on the standard illusion and reduced effects are modelled on a variant without parallels. The model shows that the effect can be ...

B E RT VA N E S , P E T E R S P R E I J 1 and HARRY VAN ZANTEN 2 Korteweg-de Vries Institute for Mathematics, University of Amsterdam, Plantage Muidergracht 24, 1018 TV Amsterdam, The Netherlands. E-mail: [email protected]; [email protected] Division of Mathematics and Computer Science, Faculty of Sciences, Free University Amsterdam, De Boelelaan 1081a, 1081 HV Amsterdam, The Netherlands...