Abstract: A system includes a container having an inner chamber for storing fluid, at least one measuring probe arranged within the chamber and one ground probe arranged within or near a bottom of the chamber. There is at least one impedance electrically connected with a processor which is electrically connected with the at least one measuring probe. A signal generator has a first voltage terminal electrically connected with the at least one impedance and a second voltage terminal electrically connected with the ground probe. When a signal is sent from the signal generator to the measuring probe, an electrochemical reaction occurs at the measuring probe and ground probe and stores a charge if the measuring probe and/or ground probe are immersed in fluid. The processor measures the voltage, current and power of the signal to calculate the resistance and capacitance of the fluid within the container to determine the level of fluid in the container.

Abstract: A sharpening filter for orthovoltage x-ray beams employs a substantially planar filter disk supporting a set of radial symmetric features controlling attenuation of x-ray transmission in concentric circular regions providing increased sharpness of the pencil beams in a compact filter structure that may be tailored to different beam sizes and focus depths.

Abstract: A system includes a container having an inner chamber for storing fluid, at least one measuring probe arranged within the chamber and one ground probe arranged within or near a bottom of the chamber. There is at least one impedance electrically connected with a processor which is electrically connected with the at least one measuring probe. A signal generator has a first voltage terminal electrically connected with the at least one impedance and a second voltage terminal electrically connected with the ground probe. When a signal is sent from the signal generator to the measuring probe, an electrochemical reaction occurs at the measuring probe and ground probe and stores a charge if the measuring probe and/or ground probe are immersed in fluid. The processor measures the voltage, current and power of the signal to calculate the resistance and capacitance of the fluid within the container to determine the level of fluid in the container.

Abstract: A sharpening filter for orthovoltage x-ray beams employs a substantially planar filter disk supporting a set of radial symmetric features controlling attenuation of x-ray transmission in concentric circular regions providing increased sharpness of the pencil beams in a compact filter structure that may be tailored to different beam sizes and focus depths.

Abstract: A one-piece tube for use as a watertube within a watertube boiler or heat exchanger has a free end section that is formed to have an integral, outward-extending circumferential ring, or flange, a spaced distance from an adjacent end face of the tube. This is preferably accomplished by radially expanding the tube within the free end section and by axially compressing the free end section to cause a portion of the tube to bulge radially outward to from the circumferential ring, or flange. The flange enables the watertube to be readily driven into engagement with a dome, manifold or like casting without the creation of leaks, such as weld leaks. The free end section of the tube that extends from the circumferential ring, or flange, to the adjacent end face of the tube can be formed with a taper such that the diameter of an outer wall of the tube progressively decreases from the circumferential ring, or flange, to the end face.