An abrasive article having certain minimum levels of permeability to fluids comprises about 40 to 80%, by volume interconnected porosity and effective amounts of abrasive grain and bond to carry out soft grinding and deep cut grinding operations. The high permeability to the passage of fluids and interconnected porosity provides an open structure of channels to permit the passage of fluid through the abrasive article and the removal of swarf from the workpiece during grinding operations.

Disclosed is a method of producing porous vitrified grinder, where melamine cyanurate is used as a pore-imparting agent. The grinder has a long life and has an improved grinding capacity.

An amplifier element amplifies RF signals. An emitter follower unit drives the amplifier element at a constant voltage corresponding to a reference voltage supplied to a reference terminal from outside. A current injection unit drives the amplifier element at a constant current corresponding to the reference voltage. An analog control unit analogically controls the output voltage of the emitter follower unit in correspondence with the control voltage supplied to a control terminal from outside. ...

Embodiments of apparatuses, articles, methods, and systems for a bias network providing a stable transient response are generally described herein. Other embodiments may be described and claimed.

An amplifier circuit and method for reducing bias noise is disclosed. The amplifier circuit includes a passive biasing source for supplying a desired bias signal to the amplifier and an active biasing source for energizing the passive biasing source to supply the desired bias signal. The amplifier circuit also includes a decoupler for selectively decoupling the active biasing source from the passive biasing source when the amplifier is configured for amplifying an input signal so that the amplif...

Abrasive foam articles and a method of manufacture of such articles are described. The articles of the invention comprise a flexible and resilient foam substrate having first and second major substrate surfaces, at least one of the surfaces having a plurality of open cells substantially across the substrate surface, the open cells having coatable surfaces defined by interconnected voids; and a plurality of abrasive particles adhered to said coatable surfaces of said open cells in a substantially...

The instant invention relates generally to abrasive stones for use in processing workpiece surfaces. The abrasive stones generally are produced by combining an epoxy novalac resin mixture with microballoons and a catalyst. The mixture is put into a mold, cold pressed, and then cured, creating abrasive stones having a uniform surface and bulk structure with a uniform hardness, suitable for workpiece processing.

the output amplifiers requiring a bias voltage can be activated or deactivated individually, and a bias acceleration circuit for rapidly increasing the magnitude of a bias voltage in time can be provided in or with the bias circuit, whereby even in case of the capacitance of the capacitor included in the bias circuit being increased for improving the power supply rejection ratio (PSRR), the rise in the bias voltage can be increased so that the pop sound which arises when the bias circuit is acti...

A vitrified abrasive element such as a grinding wheel made from a mixture of (1) abrasive grit composed primarily of aluminum oxide (Al.sub.2 O.sub.3), (2) a ceramic bonding material which may include feldspar, frit and clay and (3) a pore-forming material comprising glass cullet such, for example, as crushed or broken soda-lime glass having a strong affinity for the abrasive grit when melted by heating. The mixture is heated to vitrify the bonding material and melt the glass cullet, causing the...

Abrasive members formed with resiliently extensible and compressible preformed synthetic foam body particles compressed and bonded together with flexible bonding material and carrying abrasive grains. The combined void portion of the abrasive member and the solids portion of the foam particles occupies a substantial part of the total volume of the abrasive member, and more than 50% for members capable of conforming to contours. In one method of manufacture free preformed foam particles and abras...