Abstract: A powered garage door opener in a door assembly including a shaft coupled to a pulley with a cable to lift a garage door with an electric motor coupled to the shaft, includes a braking circuit for regulating the speed of the shaft when it is not actively powered by the electric motor. The braking circuit includes a first switch to connect a first braking resistor across the electric motor to provide a first braking force. A braking controller monitors the speed of the garage door and selectively commands a second switch to close and to connect a second braking resistor and to thereby cause the electric motor to apply a second braking force significantly greater than the first braking force. A rectifier is connected across the first braking resistor to provide power to a motor drive controller using the induced voltage from the turning electric motor.

Abstract: A system and method for managing fluid mature fine tailings (MFT) containment volume in a tailings pond to a minimum, fixed steady-state volume by balancing the accumulation of the MFT in the pond with consumption of the MFT from the pond by one or both of spiking the MFT into coarse sand tailings forming a coarse sand beach with trapped fines which is segregating for forming a trafficable deposit or centrifuging MFT from the tailings pond and depositing the resulting centrifuge cake on the coarse sand beach. During the life of the oil sand operation, when the volume of MFT approaches the fixed volume of the tailings pond, MFT is consumed from the pond using both sand-spiking and centrifugation as required. Production of MFT in the pond is also reduced by diverting an underflow from a secondary flotation cell in an extraction plant from the tailings pond to a thickener where the fines-rich thickened tailings from the thickener are beached for subsequent dewatering and reclamation.

Abstract: The invention relates to a segmented packing ring for sealed packages, comprising at least two annular segments (1), which, in the assembled state, are held together in the circumferential direction by means of springs (3). According to the invention, the assembly may be simplified and relatively small springs used as protection against damage as a result of spring breakages, whereby, at each contact point (2) of adjacent annular segments (1), at least one separate tension spring (3) is arranged between anchor elements (5) provided on both ends in the region of the ends (4) of the annular segments (1) and the fixing of the tension springs (3) to the anchor elements (5) has a preferably clip or locking mechanism for single-person operation.