Abstract: A gas receiver configured to heat a working fluid is disclosed. The receiver comprises an aperture, a light absorber, and a pre-heater interposed between the aperture and light absorber. The pre-heater is transparent to visible light and opaque to infrared. The pre-heater in the preferred embodiment comprises quartz in the form of a plurality of quartz plates or quartz tubes, for example, that are oriented substantially parallel to one another. The quartz plates are separated from one another by a gap to permit air to pass into the receiver cavity, while the quartz tubes are hollow to permit air to pass therethrough. The quartz plates or tubes are configured to transmit visible light from the aperture to the light absorber, and to absorb infrared radiation passing from the light absorber toward the aperture. Since the quartz structures absorb infrared, they serve to capture blackbody radiation emitted from the absorber and use that energy to pre-heat air before it passes into the absorber.

Abstract: A system and method for calibrating the gap between a 3D printer extruder nozzle and build platform are disclosed. To calibrate, the build platform is moved laterally in the horizontal plane and the extruder nozzle is moved downward toward the build platform. While moving the nozzle downward, the velocity of the build platform or the power required to move the build platform in the horizontal plane is monitored. A drop in velocity or an increase is power required to move the build platform is detected when the extruder nozzle contacts the build platform due to kinetic friction. The vertical height of the extruder nozzle is then set or calibrated relative to the build platform based on the position of the extruder nozzle when the contact was detected.

Abstract: A multi-gate Schottky depletion-mode field effect transistor (FET), at least one diode and two resistors comprise a compact electrostatic discharge (ESD) protection structure. This ESD protection structure can be laid out in a smaller area than typical multiple diode ESD devices. The multi-gate FET may comprise various types of high-electron-mobility transistor (HEMT) devices, e.g., (pseudomorphic) pHEMT, (metamorphic) mHEMT, induced HEMT. The multiple gates of the Schottky field effect device are used to form an ESD trigger and charge draining paths for protection of circuits following the ESD protection device. Both single and dual polarity ESD protection devices may be provided on an integrated circuit die for protection of input-output circuits thereof.

Abstract: A multi-gate Schottky depletion-mode field effect transistor (FET), at least one diode and two resistors comprise a compact electrostatic discharge (ESD) protection structure. This ESD protection structure can be laid out in a smaller area than typical multiple diode ESD devices. The multi-gate FET may comprise various types of high-electron-mobility transistor (HEMT) devices, e.g., (pseudomorphic) pHEMT, (metamorphic) mHEMT, induced HEMT. The multiple gates of the Schottky field effect device are used to form an ESD trigger and charge draining paths for protection of circuits following the ESD protection device. Both single and dual polarity ESD protection devices may be provided on an integrated circuit die for protection of input-output circuits thereof.

Abstract: A multi-gate Schottky depletion-mode field effect transistor (FET), at least one diode and two resistors comprise a compact electrostatic discharge (ESD) protection structure. This ESD protection structure can be laid out in a smaller area than typical multiple diode ESD devices. The multi-gate FET may comprise various types of high-electron-mobility transistor (HEMT) devices, e.g., (pseudomorphic) pHEMT, (metamorphic) mHEMT, induced HEMT. The multiple gates of the Schottky field effect device are used to form an ESD trigger and charge draining paths for protection of circuits following the ESD protection device. Both single and dual polarity ESD protection devices may be provided on an integrated circuit die for protection of input-output circuits thereof.

Abstract: A positioning mechanism for precisely moving a 3D printing stage in two dimensions is disclosed. The positioning mechanism consists of a first drive assembly, a second drive assembly, a moveable platform, and a stationary frame. The first and second drive assemblies each consist of a gear rack, pinion wire, and actuator. The first and second drive assemblies are configured to move the stage in orthogonal directions in a substantially horizontal plane. Both the first and second pinion wires are in direct contact with the stage as well as the frame, thereby providing an effective parallel linkage between stage and frame.

Abstract: A multi-gate Schottky depletion-mode field effect transistor (FET), at least one diode and two resistors comprise a compact electrostatic discharge (ESD) protection structure. This ESD protection structure can be laid out in a smaller area than typical multiple diode ESD devices. The multi-gate FET may comprise various types of high-electron-mobility transistor (HEMT) devices, e.g., (pseudomorphic) pHEMT, (metamorphic) mHEMT, induced HEMT. The multiple gates of the Schottky field effect device are used to form an ESD trigger and charge draining paths for protection of circuits following the ESD protection device. Both single and dual polarity ESD protection devices may be provided on an integrated circuit die for protection of input-output circuits thereof.

Abstract: Systems and methods of heliostat reflector cleaning via a vehicle in a heliostat field.

Abstract: Systems and methods of heliostat reflector cleaning via a vehicle in a heliostat field.

Abstract: Solar receivers and particularly to solar receivers having one or more cavities and optionally having absorptivity/reflectivity patterns on surfaces and methods of reflective material application.

Abstract: The present application discloses a mechanical arrangement and components for reducing errors in position estimation in mobile robotic vehicles that use deduced reckoning. The arrangement provides a method for determining the weight to be carried by the driven wheels to provide increased or maximum contact force between the driven wheels and a support surface, which in turn reduces or minimizes wheel slippage and reduces or minimizes vehicle tilting. The arrangement further provides uniquely shaped rolling elements that generate reduced sideways directed forces on the vehicle, thus reducing or minimizing wheel slippage.