Natural and artificially-initiated lightning and lightning test standards
Article Abstract:
Techniques are needed to predict lightning behavior to prevent incidents of lightning striking airborne vehicles and to protect vulnerable solid-state electronics from damage caused by lightning-induced voltages and currents. New techniques for data acquisition and recording, as well as new methods of analysis, have in turn opened up new avenues of research. The present state of knowledge about natural and triggered lightning is reviewed, the mechanisms of lightning damage and the methods of lightning protection are analyzed, including the test standards used to determine the immunity of systems from lightning, and ways to unify and provide access to current knowledge about lightning protection are suggested. Among the topics discussed are natural lightning characteristics, artificially-initiated lightning, and methods of protection.
Publication Name: Proceedings of the IEEE
Subject: Electronics
ISSN: 0018-9219
Year: 1988
User Contributions:
Comment about this article or add new information about this topic:
Atomic ion frequency standards
Article Abstract:
A new class of atomic frequency standards, based on ions trapped by electromagnetic fields, are in the early stages of development. Such standards apparently have fundamental advantages over more established types of frequency standards and have the potential of achieving higher frequency accuracy than current standards. A trapped-ion frequency standard is achieved by servoing an oscillator to a resonance corresponding to a transition between two energy levels of an atomic ion. A combination of electric and magnetic fields suspends the ions in space. These standards are capable of excellent frequency stability. Several types of trapped-ion frequency standards are under development.
Publication Name: Proceedings of the IEEE
Subject: Electronics
ISSN: 0018-9219
Year: 1991
User Contributions:
Comment about this article or add new information about this topic:
An introduction to frequency standards
Article Abstract:
The physical principles of widely-used atomic frequency standards are discussed, including a description of high performance quartz crystal standards. A basis for characterization of the practical aspects of commercially available frequency standards is provided along with a comparison of the standards, which may be used in the selection of devices for applications. The standards for quartz oscillators and rubidium, cesium, and hydrogen atomic frequency are described in terms of the physics of operation. The sources of frequency instability and inaccuracy are described.
Publication Name: Proceedings of the IEEE
Subject: Electronics
ISSN: 0018-9219
Year: 1991
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Array pattern control and synthesis. Automatic placement and routing techniques for gate array and standard cell designs
- Abstracts: Modulation and coding for satellite and space communications. Inter-system communications-networking
- Abstracts: Optical neural networks. A statistical approach to learning and generalization in layered neural networks