Abstract: This relates to methods for measuring irregularities in a signal and corresponding devices. The devices can include a PPG sensor unit configured to detect multiple occurrences of a given event in the measured signal(s) over a sampling interval. In some instances, the device can register the occurrences of the events. In some examples, the device can include one or more motion sensors configured to detect whether the device is in a low-motion state. The device may delay initiating measurements when the device is not in a low-motion state to enhance measurement accuracy. Examples of the disclosure further include resetting the sample procedure based on one or more factors such as the number of non-qualifying measurements. In some examples, the device can be configured to perform both primary and secondary measurements, where the primary measurements can include readings using a set of operating conditions different from the secondary measurements.

Abstract: A method of forming a ceramic article includes providing a ceramic body comprising silicon carbide, and treating the ceramic body in an atmosphere comprising an oxidizing material to remove a portion of the ceramic body through a chemical reaction between a portion of the ceramic body and the oxidizing material.

Abstract: A pipe choke for use in drilling and mining operations comprising a body including a first end and a second end configured to couple to a pipe, an opening extending through the body from the first end to the second end, and wherein the body includes a first phase comprising recrystallized silicon carbide and a second phase comprising silicon.

Abstract: A composite article including a body made of recrystallized silicon carbide and an infiltrant, wherein the body comprises a static impact resistance of at least about 1800 MPa.

Abstract: A composite article having a body including a first phase that includes a nitride material, a second phase that includes a carbide material, and a third phase having one of an amorphous phase material with a nitrogen content of at least about 1.6 wt % or an amorphous phase material comprising carbon.

Abstract: A method of forming a ceramic article includes providing a ceramic body comprising silicon carbide, and treating the ceramic body in an atmosphere comprising an oxidizing material to remove a portion of the ceramic body through a chemical reaction between a portion of the ceramic body and the oxidizing material.

Abstract: An article including a monolithic crucible body comprising silicon oxynitride (SixNyO, wherein x>0 and y>0), wherein the silicon oxynitride extends throughout the entire volume of the monolithic crucible body.

Abstract: A pipe choke for use in drilling and mining operations comprising a body including a first end and a second end configured to couple to a pipe, an opening extending through the body from the first end to the second end, and wherein the body includes a first phase comprising recrystallized silicon carbide and a second phase comprising silicon.

Abstract: A solid oxide fuel cell includes an anode layer, an electrolyte layer over a surface of the anode layer, and a cathode layer over a surface of the electrolyte layer. The cathode layer includes a cathode bulk layer, a porous cathode functional layer at an electrolyte, an intermediate cathode layer partitioning the cathode bulk layer and the porous cathode functional layer, the porous intermediate cathode layer having a porosity greater than that of the cathode bulk layer. The solid oxide fuel cells can be combined to form subassemblies that are bonded together to form solid oxide fuel cell assemblies.

Abstract: A composite article having a body including a first phase that includes a nitride material, a second phase that includes a carbide material, and a third phase having one of an amorphous phase material with a nitrogen content of at least about 1.6 wt % or an amorphous phase material comprising carbon.

Abstract: An article including a monolithic crucible body comprising silicon oxynitride (SixNyO, wherein x>0 and y>0), wherein the silicon oxynitride extends throughout the entire volume of the monolithic crucible body.

Abstract: A method of forming a ceramic article including providing a ceramic body comprising silicon carbide, and treating the ceramic body in an atmosphere comprising an oxidizing material to remove a portion of the ceramic body through a chemical reaction between a portion of the ceramic body and the oxidizing material.

Abstract: A composite article including a body made of recrystallized silicon carbide and an infiltrant, wherein the body comprises a static impact resistance of at least about 1800 MPa.

Abstract: A solid oxide fuel cell includes a tube, a spacer element, a catalytic substrate and an anode current collector. The solid oxide fuel cell further includes a spacer element disposed within the tube. The solid oxide fuel cell further includes a catalytic substrate disposed within the anode current collector electrically contacting the anode of the tube and providing an electrical current path inside the tube past the catalytic substrate to the inlet opening.

Abstract: A method of forming a sintered boron carbide body includes washing boron carbide powder with essentially pure water at an elevated temperature to generate low oxygen boron carbide powder, mixing a sintering aid and a pressing aid with the low oxygen boron carbide powder to form a green mixture, and shaping the green mixture into a green boron carbide body. The method can include mixing titanium carbide powder having an average particle diameter in a range of between about 5 nm and about 100 nm with the low oxygen boron carbide powder. The method can further include sintering the green boron carbide body, and hot isostatic pressing the sintered body, to a density greater than about 98.5% of the theoretical density (TD) of boron carbide. Alternatively, the method can include sintering the shaped boron carbide green body at a temperature greater than about 2,200° C., to thereby form a eutectic liquid solid solution of B4C/SiC, forming a sintered boron carbide body with a density greater than about 98% TD.

Abstract: A method of forming a sintered silicon carbide body includes mixing silicon carbide powder having an oxygen content of less than about 3 wt % and having a surface area in a range of between about 8 m2/g and about 15 m2/g, with boron carbide powder and carbon sintering aid to form a green silicon carbide body. Alternatively, a method of producing a sintered silicon carbide body includes mixing the silicon carbide powder with titanium carbide powder having an average particle diameter in a range of between about 5 nm and about 100 nm and with carbon sintering aid to form a green silicon carbide body. In another alternative, a method of forming a sintered silicon carbide body includes mixing silicon carbide powder with boron carbide powder, the titanium carbide powder, and carbon sintering aid to form a green silicon carbide body. After sintering, the silicon carbide bodies have a density at least 98% of the theoretical density of silicon carbide.

Abstract: An electrostatic dissipative (ESD) article includes a body having a volume resistivity within a range between about 104 ohm-cm and about 1010 ohm-cm as measured at 23° C. and 500 V. The body also has a first phase including a nitride, a second phase including a carbide, and a third phase including an oxide material.

Abstract: A solid oxide fuel cell comprises a plurality of tubes, each having an anode, electrolyte and cathode. Anode and cathode current collectors are mounted on the tubes. The anode current collector electrically connects to the anode and can have a contact with the anode. The cathode current collector electrically connects to the cathode and can have a contact with the cathode. An electrically conductive sealant may be positioned between the anode of one tube and the cathode current collector of another tube.

Abstract: A solid oxide fuel cell includes an anode layer, an electrolyte layer over a surface of the anode layer, and a cathode layer over a surface of the electrolyte layer. The cathode layer includes a cathode bulk layer, a porous cathode functional layer at an electrolyte, an intermediate cathode layer partitioning the cathode bulk layer and the porous cathode functional layer, the porous intermediate cathode layer having a porosity greater than that of the cathode bulk layer. The solid oxide fuel cells can be combined to form subassemblies that are bonded together to form solid oxide fuel cell assemblies.

Abstract: A gas delivery substrate and method of manufacture is disclosed. A thermoplastic extrusion compound is created comprising a ceramic material and a thermoplastic resin, a green body is formed by thermoplastic extrusion of the compound, and the green body is sintered to form the gas delivery substrate. Such gas delivery substrates may be thin walled, highly porous and have secondary operations such as crimping and machining done prior to sintering.