Refuse collection and transportation systems. (Presents status of rotary drums and clean drums.).

Material Flow in Rotary Drums

The experimental investigation of material flow in rotary drums is studied. An equipment in the size of pilot-scale was used to collect experimental data for investigation of validity of the conventional steady-state model of material flow in rotary drums. Also, the transient data of the time required for material movement in the empty drum up to any specified cross section are also reported. T...

Sealing of Rotary Drums for Operation Under Pressurized Conditions

Drums and Curve Descriptors

In this paper we present a new physically motivated curve descriptor based on the solution of Helmholtz’s equation. The descriptor satisfies the six principles set by MPEG-7: it has a good retrieval accuracy, it is compact, it can be applied in general contexts, it has a reasonable computational complexity, it is robust and provides an hierarchical representation of the curve from coarse to fin...

Eigenfrequencies of Fractal Drums Eigenfrequencies of Fractal Drums

A method for the computation of eigenfrequencies and eigenmodes of fractal drums is presented. The approach involves first mapping the unit disk to a polygon approximating the fractal and then solving a weighted eigenvalue problem on the unit disk by a spectral collocation method. The numerical computation of the complicated conformal mapping was made feasible by the use of the fast multipole m...

Eigenmodes of Isospectral Drums

Recently it was proved that there exist nonisometric planar regions that have identical Laplace spectra. That is, one cannot “hear the shape of a drum.” The simplest isospectral regions known are bounded by polygons with reentrant corners. While the isospectrality can be proven mathematically, analytical techniques are unable to produce the eigenvalues themselves. Furthermore, standard numerica...