When using shear testing to determine wall friction of pharmaceutical particulate systems, it is crucial to measure at the correct wall normal stress. By comparing data obtained at a wall normal stress of 1000 to 200 Pa, the effect of the applied stress on the accuracy and precision of the method was assessed. INTRODUCTION When powder flows under gravity from a hopper, it follows one of two pat...

This work experimentally investigates the effects of an interstitial fluid on the discharge of granular material within an hourglass. The experiments include observations of the flow patterns, measurements of the discharge rates, and pressure variations for a range of different fluid viscosities, particle densities and diameters, and hourglass geometries. The results are classified into three r...

Hierarchical Task Networks (HTNs) are a family of powerful planning algorithms that have been successfully applied to many complex, real-world domains. However, they are limited to predictable domains. In this paper we present HOPPER (Hierarchical Ordered Partial-Plan Executor and Re-planner), a hierarchical planning agent that produces partial plans in a similar way to HTNs but can also handle...

Materials and methods: A total of 54 sows and their litters were assigned to three treatments: rotary feeder with hopper, rotary feeder without hopper, and pan feeder. A creep diet with 1.0% chromic oxide was offered ad libitum from Day 18 until weaning (Day 21). Fecal samples were collected from piglets with sterile swabs 3 to 12 hours before weaning. Piglets were categorized as “eaters” when ...

This paper describes two-dimensional computer simulations of granular flow in plane hoppers. The simulations can reproduce an experimentally observed asymmetric unsteadiness for monodispersed particle sizes, but also could eliminate it by adding a small amount of polydispersity. This appears to be a result of the strong packings that may be formed by monodispersed particles and is thus a noncon...