Abstract: Embodiments described herein derive improvements to a collimator model of a multi-leaf collimator (MLC) for a dose calculation source model. The MLC has movable leaves formed of an attenuating material for a beam of radiation. The collimation model includes a 3D geometric model of the MLC. The system determines a plurality of attenuation lengths at leaf of the MLC in attenuating the beam of radiation. The beam of radiation includes a plurality of beam segments, and the plurality of attenuation lengths at leaf may be based on distance that the beamlet travels in leaf along respective beam segments. The system retrieves pre-calculated beam spectrum data for the beam of radiation, and may receive data representing the input spectrum for the beam of radiation. The system applies these data to calculate adjustments to the dose calculation source model to take into account beam hardening along the MLC geometry.

Abstract: Embodiments described herein provide for training a local neural network model that receives a first data set corresponding to parameters of a radiation therapy delivery system for delivering a radiation field to a phantom. The neural network model has been trained to determine the quantity of radiation delivered to a plurality of volume elements of the phantom based on the parameters of the first data set. The local neural network model receives local dose calculation parameters, such as total energy released per mass (TERMA) values and density values, for each voxel grid element of a high resolution voxel grid of the phantom. In an embodiment, each voxel grid element includes a central voxel and a plurality of neighboring voxels. The processor applies the neural network model to the TERMA values and the density values of the neighboring voxels to determine the quantity of radiation delivered to the central voxel.

Abstract: In a screening device, a rotor element on a rotor coaxial with a cylindrical screen drum and a cylindrical screen including: an upper surface and a front face between the surface of the rotor and the upper surface, wherein the front face faces upstream into pulp flow through a gap between the screen drum and the cylindrical screen; a trailing surface extending downstream of the pulp flow from the upper surface, wherein the trailing surface tapers to the surface of the rotor and meets the surface of the rotor at a back region of the trailing surface, and opposite sidewalls extending between the trailing surface and the surface of the rotor, wherein the opposite sidewalls gradually converge towards the back region.

Abstract: An apparatus for screening a fibrous suspension including: a housing, conduits therein at least for fiber suspension being fed, reject and accept, and a rotor and a cylindrical screen drum installed in the housing, at least one of which is rotatable, whereby a surface of the rotor is provided with rotor elements in proximity to the surface of the screen drum, whereby each rotor element includes a front surface facing a flow of the fiber suspension, an upper surface and a trailing surface sloping from the upper surface towards the surface of the rotor, wherein the trailing surface of the rotor element is curved and sidewalls of the trailing surface converge at a back point of the rotor element.

Abstract: An apparatus for screening a fibrous suspension including: a housing, conduits therein at least for fiber suspension being fed, reject and accept, and a rotor and a cylindrical screen drum installed in the housing, at least one of which is rotatable, whereby a surface of the rotor is provided with rotor elements in proximity to the surface of the screen drum, whereby each rotor element includes a front surface facing a flow of the fiber suspension, an upper surface and a trailing surface sloping from the upper surface towards the surface of the rotor, wherein the trailing surface of the rotor element is curved and sidewalls of the trailing surface converge at a back point of the rotor element.