Compact Joint Research Articles

Compact joint transform correlator with a thick photorefractive crystal

A compact joint transform correlator with a thick photorefractive crystal is presented. We demonstrate that Bragg diffraction severely limits the correlation performance in a thick crystal. To relax the Bragg limitation of the crystal a Galilean telescopic beam compression technique is used in the joint transform correlator.

Infrared signal processing using a liquid crystal television

The ability of an inexpensive liquid crystal television to modulate both coherent and incoherent infrared light is reported. Experiments demonstrating light modulation for wavelengths between 0.8 μm and 1.1 μm have been performed. Potential applications to dynamic lR scene simulators, compact joint transform correlators, and novel electron trapping processors are described.

Internally Oil-Cooled Oil-Filled Cable (Separated Type)

The internally oil-colled cable was studied for the main long-distance large power underground cable. The cooling oil of the cable is separated from the insulation oil. An unique and very compact feeding joint was developed, at which the cooling oil was extracted from or fed to the high voltage cable. The electrical and mechanical initial tests of the cable and accessories were successfuly carried out making a loop 40m long for 275 kV class.

Fatigue of a Nut and Bolt

Tension bolts are widely used in engines, in machinery of various kinds, and in structures. They have unique advantages in their contribution to ease of assembly and dismantling. They also give a comparatively rigid and compact joint, and from the standpoint of static strength are extremely efficient. Unfortunately they have not got a good reputation from the standpoint of fatigue. Some designers go to considerable trouble to avoid them. Others accept their limitations and ensure safety by care in detail design and by adopting conservative figures for design stresses. Where necessary, a limitation is placed on working life, at the expiration of which the nut and bolt are replaced by new ones.