Raytheon Company

Hughes Aircraft Company

Stephen A Gabelich

Thomas K Dougherty

John J Drab

Norman H Harris

John McHardy

William W Chen

Gregory D Tracy

Tricia Veeder

An intrusion-resistant apparatus may include a magnetic memory array disposed with an enclosure. The magnetic memory may include a plurality of magnetic memory elements, each adapted to store a binary value only in the presence of a predetermined bias magnetic field having a magnetic field strength and direction within predetermined limits. Means for providing the predetermined bias magnetic field and an encryption/decryption engine may be disposed within the enclosure. An encryption/decryption key may be stored in the magnetic memory array. The encryption/decryption key may be used by the encryption/decryption engine to encrypt and decrypt data.

Intrusion resistant apparatus and method

An erase-on-demand memory cell() includes a memory layerand a heating layerthat can heat memory layerto at least an erase-effective temperature, to erase its data contents. Memory chips() and electronic systemsinclude cells(). Electronic systems() include logic circuitryto issue a signal to initiate heating. Electronic systems() include memory chips() with one or more erase-on-demand memory cells() that include a memory layer. One or more reservoirsstore chemicals. One or more valvesretain the chemicals, and respond to a signal to open, reacting the chemicals and/or exposing memory layersto the chemicals. A method of erasing data contents of memory cells includes determining existence of an erase demand scenario, generating a signal in response to the erase demand scenario, and actuating erasure of the memory cells upon issue of the signal.

Erase-on-demand memory cell

An erosion-resistant, chemically vapor-deposited zinc sulfide window and method of making the same are disclosed. The method includes the step of immersing a chemically vapor-deposited or a hot isostatic pressed, chemically vapor-deposited zinc sulfide body into a liquid comprising gallium, the liquid having a temperature of about 600.degree. C. to about 1000.degree. C., for at least about thirty minutes to form a gallium-doped body. The gallium-doped, chemically vapor-deposited zinc sulfide body according to the invention is one capable of transmitting light having a wavelength in the range of about 300 nanometers to about 15,000 nanometers. Furthermore, the gallium-doped, chemically vapor-deposited zinc sulfide window according to the invention is capable of transmitting light, having a wavelength in the range of about 380 nanometers to about 700 nanometers have been exposed to rain erosion for 20 minutes at 470 miles per hour with a 90.degree. incidence angle, with at least about 150% more efficiency than a non-doped, chemically vapor-deposited zinc sulfide window.

Method of treating a zinc sulfide body formed by chemical vapor

An apparatus and method for measuring the dielectric constant or permittivity at a plurality of positions on a test specimen are provided. Accordingly, the present invention enables the spatial variance of the dielectric constant, i.e., the dielectric homogeneity, of the test specimen to be measured. In particular, high resolution dielectric homogeneity measurements are performed at low frequency (100 kHz to 10 MHz) using a specially designed guarded electrode assembly and a specially selected high permittivity matching liquid. The guarded electrode assembly comprises a guarded electrode surrounded by a guard electrode which is supported over a test specimen resting on a planar electrode. The test specimen and the planar electrode are immersed in a dielectric fluid. The guarded electrode as well as the guard electrode, which extends into the dielectric fluid, are translated across the test specimen while the capacitance between the guarded electrode and the planar electrode is measured. The present invention is designed so that the number of required measurements are reduced compared to other techniques for measuring permittivity. The present invention also overcomes problems associated with prior art methods such as long processing times, low accuracy, and low resolution. Accordingly, the present invention permits rapid accurate high resolution measurements of dielectric homogeneity at a significant cost reduction in contrast to prior art methods.

Precise high resolution non-contact method to measure dielectric

A simple robust sensor probe for determining the magnesium concentration in molten metal alloys in real-time. The probe provides needed process control information in molten metal technologies and has particular application to processes for removing magnesium impurities from scrap aluminum. The probe employs a specially constructed electrochemical concentration cell adapted for repeated immersions into vessels containing molten metal alloys. Specifically, the probe comprises two electrodes, both inert to a molten salt layer, to the molten metal (aluminum), and to magnesium. One electrode comprises an inverted molybdenum cup, a magnesium reference material, and a fibrous ceramic wick, e.g., yttrium oxide, for retaining molten salt therein in contact with the magnesium reference material when the sensor probe is first inserted into the molten salt layer and then into the molten aluminum layer. A readout between the two electrodes provides a measure of the electromotive force and thus a measure of the concentration of magnesium in molten aluminum during demagging of the molten aluminum.

Measuring magnesium concentrations in molten metal alloys

Precise information is obtainable concerning the position of a fluid-fluid interface (28, 33), such as between a gas and a liquid or between liquids. Such information is important for the control and automation of molten metal refining processes. Specifically, in an electrolytic process for removing magnesium from molten aluminum, knowledge of the vertical position of an interface (33) between the electrolyte and the magnesium and an interface (28) between the electrolyte and the aluminum facilitates the automatic removal of the purified metals when drained or drawn from the furnace. Heat energy is conducted through a thermocouple-heater assembly 34 to a thermocouple (38) located at its tip (36). The equilibrium temperature at the thermocouple junction is dependent upon the heat loss through tip (36). When the tip comes in contact with a fluid of different thermal conductivity, as between molten matter (29) and electrolyte (30), the equilibrium temperature at tip (36) and, thus, of the thermocouple junction will change. This change in temperature is used to determine the level of the liquid-liquid interface between molten matter (29) and electrolyte (30). This information is used to determine when the drawing of further molten material from the furnace is to be terminated, so that aluminum purified in the refining process and previously drawn through an outlet (26) will not be contaminated.

Growing community of inventors

Long Beach, CA, United States of America

Stephen A Gabelich