Abstract: A drilling system, assembly, and method may help optimize drilling in a system that involves more than one rotary tool that engages the formation. A rotary tool may be a rotary cutting tool, such as a drill bit or reamer, or some other rotary tool (e.g. stabilizer or rotary steerable tool) that has the potential to drag on the wall of the hole being drilled and take energy away from cutting. In an example, a wellbore or portion thereof is formed by rotating a first rotary cutting tool having a first cutting structure in engagement with one portion of the formation together with a second rotary cutting tool having a second cutting structure in engagement with another portion of the formation. Forces are obtained above and below the second cutting structure. One or more drilling parameter or drill bit design parameter are adjusted in relation to a force differential between the forces above and below the second cutting structure.

Abstract: A drilling system, assembly, and method may help optimize drilling in a system that involves more than one rotary tool that engages the formation. A rotary tool may be a rotary cutting tool, such as a drill bit or reamer, or some other rotary tool (e.g. stabilizer or rotary steerable tool) that has the potential to drag on the wall of the hole being drilled and take energy away from cutting. In an example, a wellbore or portion thereof is formed by rotating a first rotary cutting tool having a first cutting structure in engagement with one portion of the formation together with a second rotary cutting tool having a second cutting structure in engagement with another portion of the formation. Forces are obtained above and below the second cutting structure. One or more drilling parameter or drill bit design parameter are adjusted in relation to a force differential between the forces above and below the second cutting structure.

Abstract: A drilling system, assembly, and method may help optimize drilling in a system that involves more than one rotary tool that engages the formation. A rotary tool may be a rotary cutting tool, such as a drill bit or reamer, or some other rotary tool (e.g. stabilizer or rotary steerable tool) that has the potential to drag on the wall of the hole being drilled and take energy away from cutting. In an example, a wellbore or portion thereof is formed by rotating a first rotary cutting tool having a first cutting structure in engagement with one portion of the formation together with a second rotary cutting tool having a second cutting structure in engagement with another portion of the formation. Forces are obtained above and below the second cutting structure. One or more drilling parameter or drill bit design parameter are adjusted in relation to a force differential between the forces above and below the second cutting structure.

Abstract: The present invention relates to a method for the manufacture of a device, such as a van der Waals heterostructure device, comprising a layer of an oxide of hafnium, tantalum, zirconium, niobium, tin or rhenium, and to a device comprising the same.

Abstract: A flex shaft for a motor may comprise a hollow tubular member with first and second connector ends. In some embodiments, a thickness or wall thickness of the tubular member may be selected in accordance with a desired strength or torque the flex shaft must be capable of handling. In some embodiments, a plurality of openings may be provided in the wall of the tubular member to provide a desired level of flexibility. The plurality of openings may be arranged or patterned in numerous ways discussed herein. The flex shaft allows a shorter overall length to be used than for a conventional solid shaft.