Abstract: A method to manufacture a ceramic foam filter includes: sintering a filter body to a temperature greater than a molten metal to be filtered through the body; creating multiple tortuous path channels extending through the filter body individually having a repeated and controlled passage geometry creating a continuously changing diameter and area of a flow path through the multiple tortuous path channels causing localized increases and decreases in molten metal flow rate through the multiple tortuous path channels; and applying a mixture of at least one ceramic powder and at least one binder using additive manufacturing to shape the filter body including the multiple tortuous path channels.

Abstract: The disclosed clock adjustment method and apparatus utilizes a periodically transmitted positive or negative predetermined fixed increment clock phase adjustment signal to phase adjust the clocks of the system. The transmitter clock is periodically compared with a common reference clock and a fixed increment clock adjustment signal is transmitted to the receiver which adjusts its clock by applying the fixed increment clock adjustment signal to the common reference clock. The utilization of a predetermined fixed increment clock phase adjustment signal eliminates the need to send the resolution of the clock adjustment and hence reduces the number of data bits required to send clock information over the communication channel.

Abstract: A telautograph system allows a user at one location to write on a special surface, such as a chalkboard, and have the image appear at remote screens. Presently, a user wishing to call attention to an entry already written on the board must make a new line or must circle the item to which the remote viewer's attention is to be drawn. This procedure unduly clutters the image and a system has been devised which provides for a cursor (a graphical hand) to appear on the remote screen when the user touches the input surface at a point. The cursor also appears when the user is writing on the surface so as to call attention to the newly formed images. When pressure on the writing surface is released the cursor remains on the remote screen for a finite period and then automatically disappears, leaving the image unencumbered. When information is being removed from the input surface a graphical eraser appears at the remote screen at the site of the removed information.