Abstract: Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.

Abstract: A control system for controlling extraction of landfill gas, comprising: at least one sensor configured to measure one or more characteristics of landfill gas; at least one flow control mechanism disposed in well piping and configured to control flow of the landfill gas through the well piping; and at least one processor configured to: obtain a measured concentration of a first gas in landfill gas; determine whether the measured concentration of the first gas is either less than a first threshold concentration or greater than a second threshold concentration; when it is determined that the measured concentration is less than the first threshold concentration, control the at least one flow control mechanism to reduce flow rate of landfill gas; and when it is determined that the concentration is greater than the second threshold concentration, control the at least one flow control mechanism to increase the flow rate of landfill gas.

Abstract: Described herein are embodiments of a control system that automatically (1) determines whether a gas extraction system is in a state in which landfill gas is being released into the atmosphere, and (2) automatically controls landfill gas flow to mitigate, prevent and/or stop the release of landfill gas. The control system may control a valve to control flow of landfill gas through well piping of the gas extraction system. The pressure of landfill gas in the well piping at a location upstream of the valve may indicate whether there is a risk of landfill gas being released into the atmosphere. The control system may adjust a position of the valve in response to determining that the pressure at the location upstream of the valve indicates that there is a risk of landfill gas being released into the atmosphere.

Abstract: An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.

Abstract: Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.

Abstract: A control system for controlling extraction of landfill gas, comprising: at least one sensor configured to measure one or more characteristics of landfill gas; at least one flow control mechanism disposed in well piping and configured to control flow of the landfill gas through the well piping; and at least one processor configured to: obtain a measured concentration of a first gas in landfill gas; determine whether the measured concentration of the first gas is either less than a first threshold concentration or greater than a second threshold concentration; when it is determined that the measured concentration is less than the first threshold concentration, control the at least one flow control mechanism to reduce flow rate of landfill gas; and when it is determined that the concentration is greater than the second threshold concentration, control the at least one flow control mechanism to increase the flow rate of landfill gas.

Abstract: An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.

Abstract: A control system for controlling extraction of landfill gas from a landfill via a gas extraction system comprising well piping, the landfill gas having a first temperature when extracted, the control system comprising: a gas composition chamber coupled to the well piping and comprising at least one sensor configured to measure one or more characteristics of a landfill gas sample in the gas composition chamber; a temperature control mechanism configured to heat the landfill gas sample in the gas composition chamber to a second temperature at least a threshold amount greater than the first temperature; and a controller configured to control the at least one sensor to measure the one or more characteristics of the landfill gas sample in the gas composition chamber when a temperature of the landfill gas sample in the gas composition chamber is at least the threshold amount greater than the first temperature.

Abstract: Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.

Abstract: A control system for controlling extraction of landfill gas from a landfill via a gas extraction system comprising well piping, the landfill gas having a first temperature when extracted, the control system comprising: a gas composition chamber coupled to the well piping and comprising at least one sensor configured to measure one or more characteristics of a landfill gas sample in the gas composition chamber; a temperature control mechanism configured to heat the landfill gas sample in the gas composition chamber to a second temperature at least a threshold amount greater than the first temperature; and a controller configured to control the at least one sensor to measure the one or more characteristics of the landfill gas sample in the gas composition chamber when a temperature of the landfill gas sample in the gas composition chamber is at least the threshold amount greater than the first temperature.

Abstract: A system for extracting landfill gas from a landfill is provided. According to some embodiments, a control system for landfill gas extraction is provided. The control system uses a throttle to control flow of landfill gas extracted from the landfill. The throttle is actuated in use to vary the flow of gas between a well and a gas collection system, in accordance with a control algorithm that adjusts flow as a parameter in controlling gas extraction. The throttle is configured to ensure that there is at least some flow of landfill gas from the landfill to a gas output throughout operation. The extraction system provides an efficient system for landfill gas extraction, while mitigating a risk of creating undesired or unpleasant conditions and/or of violating regulations during operation.

Abstract: Described herein are embodiments of a control system that automatically (1) determines whether a gas extraction system is in a state in which landfill gas is being released into the atmosphere, and (2) automatically controls landfill gas flow to mitigate, prevent and/or stop the release of landfill gas. The control system may control a valve to control flow of landfill gas through well piping of the gas extraction system. The pressure of landfill gas in the well piping at a location upstream of the valve may indicate whether there is a risk of landfill gas being released into the atmosphere. The control system may adjust a position of the valve in response to determining that the pressure at the location upstream of the valve indicates that there is a risk of landfill gas being released into the atmosphere.

Abstract: Described herein are embodiments of a control system that automatically (1) determines whether a gas extraction system is in a state in which landfill gas is being released into the atmosphere, and (2) automatically controls landfill gas flow to mitigate, prevent and/or stop the release of landfill gas. The control system may control a valve to control flow of landfill gas through well piping of the gas extraction system. The pressure of landfill gas in the well piping at a location upstream of the valve may indicate whether there is a risk of landfill gas being released into the atmosphere. The control system may adjust a position of the valve in response to determining that the pressure at the location upstream of the valve indicates that there is a risk of landfill gas being released into the atmosphere.

Abstract: Bone joint implants are described herein. The bone joint implants may comprise a metallic proximal platform configured for translational motion on the trapezium bone; a distal stem configured for intramedullary engagement with an end of the first metacarpal bone; an articulating coupling between the proximal platform and distal stem; and a proximal non-metallic wear surface and a distal non-metallic wear surface.

Abstract: A system for extracting landfill gas from a landfill is provided. According to some embodiments, a control system for landfill gas extraction is provided. The control system uses a throttle to control flow of landfill gas extracted from the landfill. The throttle is actuated in use to vary the flow of gas between a well and a gas collection system, in accordance with a control algorithm that adjusts flow as a parameter in controlling gas extraction. The throttle is configured to ensure that there is at least some flow of landfill gas from the landfill to a gas output throughout operation. The extraction system provides an efficient system for landfill gas extraction, while mitigating a risk of creating undesired or unpleasant conditions and/or of violating regulations during operation.

Abstract: Bone joint implants are described herein. The bone joint implants may comprise a metallic proximal platform configured for translational motion on the trapezium bone; a distal stem configured for intramedullary engagement with an end of the first metacarpal bone; an articulating coupling between the proximal platform and distal stem; and a proximal non-metallic wear surface and a distal non-metallic wear surface.

Abstract: A control system for controlling extraction of landfill gas from a landfill via a gas extraction system, the gas extraction system comprising well piping for coupling a plurality of wells to a gas output. The control system comprises a controller configured to: obtain a value indicating measured energy content of landfill gas collected at the gas output from the plurality of wells; determine whether the measured energy content is different from a target energy content; and in response to determining that the measured energy content is different from the target energy content: control a plurality of valves disposed in the well piping to change flow rates of landfill gas being extracted from at least some of the plurality of wells at least in part by changing degrees to which the plurality of valves are open.

Abstract: A control system for controlling extraction of landfill gas from a landfill via a gas extraction system, the gas extraction system comprising well piping for coupling a plurality of wells to a gas output. The control system comprises a controller configured to: obtain a value indicating measured energy content of landfill gas collected at the gas output from the plurality of wells; determine whether the measured energy content is different from a target energy content; and in response to determining that the measured energy content is different from the target energy content: control a plurality of valves disposed in the well piping to change flow rates of landfill gas being extracted from at least some of the plurality of wells at least in part by changing degrees to which the plurality of valves are open.

Abstract: Bone joint implants are described herein. The bone joint implants may comprise a metallic proximal platform configured for translational motion on the trapezium bone; a distal stem configured for intramedullary engagement with an end of the first metacarpal bone; an articulating coupling between the proximal platform and distal stem; and a proximal non-metallic wear surface and a distal non-metallic wear surface.

Abstract: Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.