Abstract: Systems and methods for pressure testing of production tubing in an oil or gas well utilizing a valve having a first and second cylindrical body arranged for axial movement within a cylindrical housing. Movement within the cylindrical housing is regulated by introduction of hydraulic fluid into a cavity in the cylindrical housing and a spring. Systems and methods may further include the use of configuring the cylindrical bodies for sealing engagement with one another caused by movement of the cylindrical bodies within the cylindrical housing.

Abstract: Containers having a skim coat layer for improved punctureability, and sheet stock materials for and methods of making such containers are provided. A container is formed of a first material layer that contains a monolayer of polypropylene homopolymer in an amount of at least 70 percent by weight, or a multilayer material in which at least one layer comprises a polypropylene homopolymer in an amount of at least 70 percent by, and a second material layer adjacent the first material layer and forming an innermost layer adjacent the cavity, the second material layer containing a polypropylene copolymer in an amount of at least 60 percent by weight.

Abstract: In one general aspect, systems and methods are described for determining positional data for three-dimensional interactions inside virtual reality environments. The methods may include receiving inertial measurement unit (IMU) data from at least one mobile device of a plurality of mobile devices operating in a virtual reality environment, obtaining absolute position and orientation data from at least one tracked controller, comparing the IMU data from the at least one mobile device with the absolute position and orientation data of the at least one tracked controller, detecting a correlation between the IMU data from the at least one mobile device and the absolute position and orientation data of the at least one tracked controller. Based on the detected correlation, the method may include determining absolute position and orientation for the at least one mobile device based on a determined relative orientation for the at least one tracked controller.

Abstract: In one general aspect, systems and methods are described for determining positional data for three-dimensional interactions inside virtual reality environments. The methods may include receiving inertial measurement unit (IMU) data from at least one mobile device of a plurality of mobile devices operating in a virtual reality environment, obtaining absolute position and orientation data from at least one tracked controller, comparing the IMU data from the at least one mobile device with the absolute position and orientation data of the at least one tracked controller, detecting a correlation between the IMU data from the at least one mobile device and the absolute position and orientation data of the at least one tracked controller. Based on the detected correlation, the method may include determining absolute position and orientation for the at least one mobile device based on a determined relative orientation for the at least one tracked controller.

Abstract: A lumber stacker apparatus for moving a course of lumber and depositing the course on a stack of lumber includes a crank mechanism, a fork assembly, an arm member, and motor means. The crank mechanism is operatively engaged to the fork assembly by the arm member. The arm member has a crank arm affixed to a crank shaft to move the fork assembly in a reciprocating stroke in response to rotation of the crank shaft. The motor means is operatively connected to the crank shaft to rotate the crank shaft at a constant angular velocity through 200° to 260°, preferably 230°, to drive the fork assembly through a slow forward stroke, to move the course of lumber, and to rotate the crank shaft through 100° to 160°, preferably 130°, to drive the fork assembly through a rapid backward stroke once the course of boards has been deposited on the stack of lumber.