Abstract: Magnetorheological materials are provided comprising magnetic particles, a polymeric gel and a carrier material. The polymerization of the gel is preferentially accomplished in the presence of the magnetic particles and the carrier material. Magnetorheological materials are provided having a selected off-state viscosity and a selected on-state apparent viscosity. The method of preparing these magnetorheological materials is also provided. The carrier material, the polymeric gel and the magnetic particles are selected so that the resulting magnetorheological material has the desired off-state viscosity and on-state apparent viscosity. These materials have good dispersion characteristics, reduced settling, superior off-state viscosity and superior apparent viscosity in the presence of a magnetic field.

Abstract: Magnetorheological materials are provided comprising magnetic particles, a polymeric gel and a carrier material. The polymerization of the gel is preferentially accomplished in the presence of the magnetic particles and the carrier material. Magnetorheological materials are provided having a selected off-state viscosity and a selected on-state apparent viscosity. The method of preparing these magnetorheological materials is also provided. The carrier material, the polymeric gel and the magnetic particles are selected so that the resulting magnetorheological material has the desired off-state viscosity and on-state apparent viscosity. These materials have good dispersion characteristics, reduced settling, superior off-state viscosity and superior apparent viscosity in the presence of a magnetic field.

Abstract: An intrusion detector system with a transmitter having a clock operating at a selected frequency, a pseudorandom code sequence generator for generating one of a selected number of codes, a modulator for spread-spectrum modulating an electromagnetic signal with the generated pseudorandom code sequence signal, and an antenna for transmitting the modulated signal through a zone of protection; and a receiver having an antenna, a demodulator for detecting and demodulating the modulated signal to recover the transmitter pseudorandom code sequence signal, a clock operating at a frequency corresponding to the transmitter clock, a pseudorandom code sequence generator for generating one of a selected number of receiver code signals corresponding to the transmitter code signals, a detector for comparing the received code signal to the receiver code signal and generating a detection signal proportional to the signal amplitude of the received code signal when locked in phase with the receiver code signal, a phase detector