Abstract: A ceramic munitions projectile, particularly useful for practice or target munitions is provided. The projectile has a tensile strength greater than about 250 MPa, a critical stress intensity factor greater than about 6 MPam.sup.1/2, and a Weibull modulus greater than about 10. Preferably the projectile is frangible.

Abstract: A ceramic munitions projectile, particularly useful for practice or target munitions is provided. The projectile is preferably made of zirconia which is densified by a pressureless sintering method. The projectile has sufficient toughness to withstand acceleration and torque created during projectile firing and trajectory.

Abstract: A wheelchair mounted control system may be activated to enable propelling of the wheelchair at different predetermined speeds, to cause portions of the wheelchair to recline or be elevated, or to cause a signal to be generated to operate other apparatus such as a book page turner, a light switch or a television tuner, merely by positioning the neck or other skin-exposed body portion of a person in the wheelchair who is otherwise largely incapable of movement. Particular structure includes a periodic electric field source and a pair of field pickup elements adapted to be selectively contacted by the skin of a movable portion of the disabled person's body to cause, for example, activation of stepping switches and associated control relays whereby wheelchair drive motor speed is preselected and recline/elevation motor apparatus is activated for effecting the desired control of various adjustable portions of the wheelchair.