OBJECTIVES Implant surface modifications are intended to enhance bone integration. The objective of this study was to assess the effect of different surface treatments on the resistance to hydrothermal degradation, hardness and elastic modulus of a 3Y-TZP ceramic used for dental implants. METHODS Samples grouped according to their surface morphologies (AS, as-sintered; C, coated; P, dry-polis...

Summary In this study, to investigate how gravity affects foam in open vertical fractures, we report experiments three 1-m-long, 15-cm-wide glass-model fractures. Each fracture has a smooth wall and roughened wall. Between the two walls is slit-like channel representing single geological fracture. Three model fractures (Models A, B, C) share same roughness have different hydraulic apertures of ...

Peritoneal macrophages were plated out on a series of artificial haptotactic substrata consisting of grid patterns of vacuum-evaporated palladium metal alternating with hydrophobic untreated polystyrene and with hydrophilic sulphonated polystyrene. By their active locomotion the macrophages accumulated preferentially onto the less hydrophilic of either pair of these alternative substrata. This ...

an Asymmetric Spin Hamiltonian Leh-Hun Gwa Department of Mathematics, Rutgers University New Brunswick, NJ 08903, USA Herbert Spohn Theoretische Physik, Universit at M unchen Theresienstr. 37, D-8000 M unchen 2, Germany Abstract For a particular choice of vertex weights the two-dimensional six vertex model can be viewed as a probabilistic cellular automaton. Physically it describes then the ...

Two dimensional lubrication approximation is applied to the analysis of fluid flow in a rectangular microchannel with structured roughness. Each of two major walls is composed of designed microscale transverse ribs, modeled by twodimensional functions. A pressure drop correlation is formed as a direct function of these surface equations and the resultant velocity profile is incorporated into bo...

introduction: surface roughness can increase the retention of castings by ridges and grooves that are microretentive. this study compared the retention of implant-supported crowns when used with 3 different surface roughness abutments and one temporary cement. methods: thirty solid abutments (iti), 4 mm high, were divided into three groups randomly. in the first group, 10 abutments were roughen...

in a novel dual bed reactor fischer-tropsch synthesis was studied by using two diffrent cobalt catalysts. an alkali-promoted cobalt catalyst was used in the first bed of a fixed-bed reactor followed by a rutenuim promoted cobalt catalyst in the second bed. the activity, product selectivity and accelerated deactivation of the system were assessed and compared with a conventional single bed react...