A new flow enhancement system is developed for cohesive powders. It is based on the concept of multiple, point source, internal excitations. In this system, a mass of small permanent-magnetic particles are placed in the discharge zone of a hopper, and then an oscillating magnetic field is applied to excite these magnets. A screen is placed at the exit to keep the magnets within the hopper. The ...

A number of considerations should be taken into account in design stage to avoid the foregoing malfunctions of vertical silos containing ore concentrate. One of the silo problems is obstruction at the outlet which blocks the material flow. There are procedures, depending on the material properties and silo dimensions, to solve this problem. A common way is impacting the silo wall by manual hamm...

Hopper and Thompson (1980) defined a multiaxis theory of transitivity that goes beyond simple syntactic transitivity and captures how much “action” takes place in a sentence. Detecting these features requires a deep understanding of lexical semantics and real-world pragmatics. We propose two general approaches for creating a corpus of sentences labeled with respect to the Hopper-Thompson transi...

TiO2 Prepared by Hydrothermal Synthesis E. Mitchell Hopper, Frédéric Sauvage,§,¶,k Aravind Kumar Chandiran, Michael Grätzel, Kenneth R. Poeppelmeier,k and Thomas O. Mason Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 Laboratory of Photonics and Interfaces, Institute of Chemistry and Chemical Engineering, Swiss Federal Institute of Technology (EPFL)...

The Sinhala volitive/involitive contrast is characterized by verb stem and subject case marking alternations, and broadly indicates the volitionality/non-volitionality of the subject, plus other co-varying features. While superficially a high/low transitivity split à la Hopper and Thompson (1980), we argue that the distinction actually emerges from the interaction of just two factors: a realis/...

Locusts exhibit two interconvertible behavioral phases, solitarious and gregarious. While solitarious individuals are repelled from other locusts, gregarious insects are attracted to conspecifics and can form large aggregations such as marching hopper bands. Numerous biological experiments at the individual level have shown how crowding biases conversion towards the gregarious form. To understa...

In this paper, we describe modeling and control techniques for a real-world series-elastic actuated 1D hopping robot. There is an abundance of work regarding the implementation of highly simplified hopper models, with the hopes of extracting fundamental control ideas for running and hopping robots. However, real-world systems unfortunately cannot be accurately described by such simple models, a...

The beach hopper amphipod Talorchestia quoyana is not distributed homogeneously in its sandy beach habitat, but instead occurs in dense patches under large pieces of tidal debris. This marked patchiness on a scale of just a few metres may create a higher level of aggregation among hosts for the symbionts and parasites of beach hoppers. Prevalence of infection by a mermithid nematode parasite va...

We experimentally investigate the response to perturbations of circular symmetry for dense granular flow inside a three-dimensional right-conical hopper. These experiments consist of particle tracking velocimetry for the flow at the outer boundary of the hopper. We are able to test commonly used constitutive relations and observe granular flow phenomena that we can model numerically. Unperturbe...