BACKGROUND Orthodontists are commonly faced with the decision of what to do with debonded or inaccurately positioned brackets. An economical option to this dilemma is to recycle the brackets. Many recycling methods have been proposed, but the optimal bond strength of these recycled brackets needs further evaluation. Objectives: To evaluate and compare the effect of three recycling methods: (i) ...

Weak lensing by large-scale structure allows a direct measure of the dark matter distribution. We have used parallel images taken with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope to measure weak lensing, or cosmic shear. We measure the shapes of 26036 galaxies in 1292 STIS fields and measure the shear variance at a scale of 0.51 arcminutes. The charge transfer ...

Circular simple shear extrusion process was introduced as a new geometry for simple shear extrusion technique to fabricate ultrafine-grained materials. Similar to the simple shear extrusion method, this process is also based on direct extrusion, and the samples deform in a simple shear manner. In this investigation, the simulations were carried out using the commercial finite element code ABAQU...

Continuity and momentum equations govern the pore-scale flow properties of fluid in porous media, whereas Darcy’s law governs Darcy scale transport media. The empirical shift factor relates steady shear-dependent viscosity non-Newtonian fluids to reported values cover three orders magnitude depending on considered fluid-medium configurations. This creates a challenge upscale rheology from scale...

OBJECTIVE To compare shear bond strength of different direct bonding techniques of orthodontic brackets to acrylic resin surfaces. METHODS The sample comprised 64 discs of chemically activated acrylic resin (CAAR) randomly divided into four groups: discs in group 1 were bonded by means of light-cured composite resin (conventional adhesive); discs in group 2 had surfaces roughened with a diamo...

This paper reports an experimental investigation of the characteristics of local dissipation length-scale field  in turbulent (round and square) jets with various jet-exit Reynolds numbers. Results reveal that the probability density function (PDF) of , denoted by Q(), in the central fully-turbulent region, is insensitive to initial flow conditions and the departure from anisotropy. Excellen...

Foam injection is becoming a standard conditioning agent when tunnelling with an earth-pressure balanced shield, resulting in an increasing interest in this technique. The technique is mostly based on empirical rules and experience. To be able to determine what foam and how may foam has to be injected for different soils, it is necessary to know the mechanical parameters of the foam-water-soil ...

Weak bonding between layers of pavement leads to damages on the composite pavement. Bonding plays an important role in the durability and maintenance of composite pavement layers. The present study evaluates the factors effective in bond strength of the interface between concrete and asphalt pavements. The factors considered for this purpose include steel slag percentage in the concrete pavemen...