Experimental Operation of a Multichannel Laser Communication Link

The results of more than a half-year of operation of a multichan nel laser link of telephone communication of 24 km length are given. The installations for carrying out some investigations of the properties of the atmospheric channel are briefly described.     

The effects of hypokinesia in primates on bone strength.

A 14 days ground based primate hypokinesia investigation was conducted to determine what changes, if any, in bone strength may be demonstrated following 2 weeks cast immobilization and at 14 davs after removal from casts. Controlled compressive loads were applied to vertebral bodies excised from control, 2 weeks immobilization and 2 weeks post immobilization Rhesus monkeys. The material properties reported herein are ultimate load, displacement to ultimate load, stiffness and energy to ultimate load. These results show a decrease in bone strength following immobilization and a still further decrease in bone strength after 14 days.