Optical search for gamma-ray bursts

The preliminary results from optical search for light pulses associated with gamma ray bursts by means of the Czechoslovak Fireball Network plate collection at the Ondřejov observatory are given. Optical monitoring represents more than 7700 hours, but no real optical counterpart was found. Problems associated with the optical search for gamma ray bursts are discussed.     

Cellular Mobile Telephone Environment

Cellular mobile telephone systems are rapidly going into service throughout the Continental United States. They are being installed in a large variety of vehicles both of domestic and of foreign manufacture. In this paper we discuss the physical, climatic, and electronic environments which cellular telephones may expect to encounter in nationwide service. We also discuss procedures used to evaluate the ability of a cellular phone to operate without failure in these environments and to avoid interfering with the increasingly complex vehicular electronic systems.     

Prismatic lithium-ion batteries

Lithium-ion (Li-ion) batteries have demonstrated the ability to fulfill the energy storage needs of many new technologies. The most significant drawbacks of currently available technologies, such as LiCoO ₂ based Li-ion cells, is their high cost and significant environmental hazards. Li-ion cells which use a lithium manganese oxide (LiMn₂O₄) spinel based cathode material should be much less costly and safer than LiCoO₂ based cells. Performance data from prismatic design cells which use a LiMn₂O₄ based cathode material is presented and shown to meet many military performance criteria. The most significant drawback of this technology is the short cycle life