Abstract: A method for mirroring virtual machines from a primary host to a secondary host. The method includes tracking changes for each of a plurality of memory pages and processor states for one or more primary host virtual machines. Responsive to an occurrence of a checkpoint, the primary host virtual machines are stopped. A determination is made if each of the memory pages is frequently changed. In response to the memory page being frequently changed, the frequently changed memory page is marked as being writeable and copied to a buffer. In response to the memory page being infrequently changed, the infrequently changed memory page is marked as being read only. The one or more primary host virtual machines are resumed. A copy of the memory pages, the buffer and changes to the processor states are transmitted to the secondary host.

Abstract: A system and a computer program product for selecting a primary-secondary host pair for mirroring virtual machines. The system includes a processor collecting data related to each of a plurality of potential primary-secondary host pairs in a computer network. The processor analyzes each of the plurality of potential primary-secondary host pairs in the computer network utilizing performance metrics. An ideal primary-secondary host pair in the computer network is determined by the processor based on the analysis of the performance metrics of each of the plurality of potential primary-secondary host pairs. In response to determining the ideal primary-secondary host pair, a primary host virtual machine is mirrored onto the secondary host of the primary-secondary host pair.

Abstract: A method for operating a multi-stage combustor of a gas turbine engine comprises: (a) determining a combustor air entry temperature; (b) determining the combustor air entry flow rate; and (c) controlling the fuel split ratio to stages of the combustor on the basis of the combustor air entry flow rate and the combustor air entry temperature.

Abstract: The invention relates to a method of boring a hole using a boring system constituted by a simple auger and a dip tube slidably mounted in said auger, said dip tube being provided at its bottom end with a tool. The method comprises the following steps: causing said auger and said dip tube to descend and to rotate simultaneously, said tool on the dip tube being substantially level with the bottom end of the auger; interrupting the descent and rotation of said auger so that the auger constitutes anchor means for anchoring the boring system in the ground; and causing the dip tube to descend and rotate on its own, whereby the tool of the dip tube performs boring by displacing ground at the bottom end of the borehole, thereby compacting the ground.

Abstract: The invention relates to a method of boring a hole using a boring system constituted by a simple auger and a dip tube slidably mounted in said auger, said dip tube being provided at its bottom end with a tool.

Abstract: A machine for making bored piles. The machine includes a vertical guide mast; a rotary drive head that is movable relative to the mast; and an auger having a hollow core and at least one helical blade. An extender tube has a bottom end that is secured to the top end of the auger, the drive head co-operating with the extender tube to rotate both the extender tube and the auger. A dip tube is slidably mounted in the hollow core of the auger and the extender tube, the dip tube having a top end connected to a concrete feed pipe. An annular actuator has a first end secured to the top end of the extender tube and a second end secured to the top end of the dip tube.

Abstract: The invention relates to a machine for making bored piles. The machine comprises a vertical guide mast; a rotary drive head that is movable relative to the mast; an auger having a hollow core and at least one helical blade; an extender tube whose bottom end is secured to the top end of the auger, said drive head co-operating with said extender tube to rotate both the extender tube and the auger; a dip tube slidably mounted in the hollow core of the auger and the extender tube, the dip tube having a top end connected to a concrete feed pipe; and an annular actuator having a first end secured to the top end of said extender tube and a second end secured to the top end of said dip tube.