Abstract: Resistance of a selected memory cell in a Magnetic Random Access Memory (“MRAM”) device is sensed by a read circuit including a differential amplifier, a first current mode preamplifier coupled to a sense node of the differential amplifier, and a second current mode preamplifier coupled to a reference node of the differential amplifier. During a read operation, the first preamplifier applies a regulated voltage to the selected memory cell, and the second preamplifier applies a regulated voltage to a reference cell. A sense current flows through the selected memory cell and to the sense node of the differential amplifier, while a reference current flows through the reference cell and to the reference node of the differential amplifier. Resulting is a differential voltage across sense and reference nodes. The differential voltage indicates whether a logic value of ‘0’ or ‘1’ is stored in the selected memory cell.

Abstract: A measuring system for use with automated pipettes for determining the presence or absence of a pipette tip. The central conduit of the pipette is connected to a source of pressure waves, such as a speaker and also connected to a pressure wave detector, such as a microphone. Changes in acoustic impedance between an open conduit when no tip is present, a partially constricted conduit when a tip is present, and a closed conduit when the liquid boundary layer is contacted determine the measured states of the apparatus.

Abstract: A food spoilage indicator comprising a liquid crystal disposed in a carrier of plastic tape, at least one portion of which is semi-permeable to gases generated in food spoilage.

Abstract: This invention relates to Cold-Formulated Slurry Explosives with Ultra-Fine Oxidizer Solids and including perchlorates.

Abstract: The present invention relates to a pump truck for handling aqueous slurry blasting agents. The truck is designed to mix and pump the slurry without the use of augers, electrical drives, hydraulic drives, ingredient flow drive motors or other such equipment, resulting in increased safety and improved function.

Abstract: A cable employing device for securing frames to poles and posts; a cable dispensing and recovering casing secureable to a frame which includes releaseable engaging means for one cable end; an improved tensioning system for a cable dispensing casing which ordinarily retains the cable in the casing and returns the cable to the casing after use; a cable retention and return device for use in a cable dispensing container which employs a length of surgical tubing to power the cable retention and return; hinged enclosures for simultaneous enclosure of a cable dispensing system and engagement of a frame support.