Abstract: A method for volume ray casting is provided. For each pixel of a 2D image placed in a view plane a ray of sight is projected through a volume determined by a plurality of voxels of a volumetric dataset indicative of an object. A plurality of sampling points is determined along each ray of sight such that a distance between two consecutive sampling points is larger at a larger distance to the view plane. At each sampling point a color value and a transparency value is determined in dependence upon voxels in proximity of the sampling point and a lighting calculation, wherein for the lighting calculation a first lighting model and a second lighting model are used in dependence upon a distance of the sampling point to the view plane. For each ray of sight a final color value is determined by compositing along the ray the color values and the transparency values. The final color value of each ray corresponds to a pixel value of the 2D image.

Abstract: An apparatus and process are provided for controlling the heating and melting of a material that is non-electrically conductive in the solid state and is electrically conductive in the non-solid state. Power is selectively directed between coil sections surrounding different zones of the material in a susceptor vessel by changing the output frequency of the power supply to the coil sections. Coil sections comprise at least one active coil section, which is connected to the output of the power supply, and at least one passive coil section, which is not connected to the power supply, but is connected in parallel with a tuning capacitor so that the at least one passive coil section can be selectively operated at, or near, resonant frequency when the transition material in the vessel is molten.

Abstract: A system and method for computing the parameters of a forge welding machine for the forge welding of one or more materials is provided. A computer program executes a self-tuning routine to compute the operating frequency and operating power setting for the forge welding machine in response to an inputted width of the heat affected zone and an inputted weld temperature.

Abstract: An apparatus and process are provided for casting liquid metals into molds in a casting furnace comprising a controlled environment melt chamber and a mold lock chamber. A mold is supplied to the controlled environment melt chamber for a pour, and removed from the same chamber via a mold lock chamber. A mold transport system moves the mold through the mold lock chamber. The mold transport system comprises a rotary screw drive, a cylinder screw drive, or hydraulic drive located external to the furnace. Alternatively the mold transport system comprises a rack and worm screw drive.

Abstract: A tooth cleaning apparatus having a tooth scrubbing assembly and a handle through which a cleaning portion of the tooth scrubbing assembly can be placed in operative relationship to a user's teeth and borne against surfaces of a user's teeth. The tooth scrubbing assembly is configured so that at least one of a) the cleaning portion of the tooth scrubbing assembly is preformed in a curved shape to conform to a curved arrangement of inside surfaces of a user's front teeth and b) a part of the tooth scrubbing assembly is flexible to allow conforming of the cleaning portion of the tooth scrubbing assembly to the curved arrangement of inside surfaces of a user's front teeth under a pressure as applied by a user during a tooth cleaning operation.

Abstract: An impeder for use in an electric induction welding process is provided. Optionally the impeder does not require internal forced cooling. In embodiments using internal forced cooling a high efficiency cooling system is provided.

Abstract: The invention relates to electrical oscillators arranged to oscillate so as to produce a substantially sinusoidal output signal. The said oscillator includes a general impedance transvertor circuit arrangement having two differential amplifiers connected only to a plurality of resistive and capacitive impedance elements and arranged to simulate a tuned circuit with sufficient feedback to maintain oscillation within the tuned circuit. The transvertor circuit is an active device in the form of an impedance invertor circuit or a convertor circuit.

Abstract: The invention relates to electrical oscillators arranged to oscillate so as to produce a substantially sinusoidal output signal. The said oscillator includes a general impedance transvertor circuit arrangement having two differential amplifiers connected only to a plurality of resistive and capacitive impedance elements and arranged to simulate a tuned circuit with sufficient feedback to maintain oscillation within the tuned circuit. The transvertor circuit is an active device in the form of an impedance invertor circuit or a convertor circuit.

Abstract: An active network incorporating a gyrator, having a first and a second operational amplifier each said operational amplifier having an inverting input and a non-inverting input, the inverting inputs of said first and said second operational amplifiers being directly connected, and wherein the outputs of said first and said second operational amplifiers are resistively connected to the inverting inputs of said operational amplifiers, an input terminal is connected to said non-inverting input of said first operational amplifier which said input terminal is connected resistively to said output of said second operational amplifier, said output of said first operational amplifier is capacitively coupled to said non-inverting input of said second operational amplifier and said non-inverting input of said second operational amplifier is resistively connected to earth.

Abstract: This invention concerns gyrator circuits, and particularly gyrator circuits used in filters. The gyrator network contains two differential input operational amplifiers and an input network, some of the elements of which are variable to enable the Q, the bandwidth and the resonant frequency to be adjusted in such a way that previously adjusted parameters are not changed. The circuit may have three configurations according to the position of a pair of ganged switches, alternatively the switches may be replaced by fixed links.

Abstract: A filter network particularly suitable for construction in micro-electronic circuitry for application in telephony systems is formed by simulating inductance in a circuit arrangement incorporating only resistance, capacitance and amplifying elements. The symmetry of the circuit arrangement and coupling into the filter network simplifies fabrication and reduces the number of amplifiers previously required to perform similar filter functions. The filter networks may be built up by coupling a chain of circuit arrangements each including two unity gain amplifiers having a series resistor/capacitor feedback network and a non-inductive element interconnecting the two amplifier feedback networks.