447 resultados para SPARK
Resumo:
An analysis of the time-dependent resistive voltage and power deposition during the breakdown phase of pseudo-spark is presented. The voltage and current were measured by specially designed low-inductance capacitive voltage divider and current measuring resistor. The measured waveforms of voltage and current are digitized and processed by a computer program to remove the inductive component, so as to obtain resistive voltage and power deposition. The influence of pressure, cathode geometry and charging voltage of storage capacitors on the electrical properties in the breakdown phase are investigated. The results suggest that the breakdown phase of pseudo-spark consists of three stages. The first stage is mainly hollow cathode discharge. In the second stage, field-enhanced thermionic emission takes place, resulting in a fast voltage drop and sharp rise of discharge current. The third stage of discharge depends simply on the parameters of the discharge circuit.
Resumo:
The First SPARK-STREAM Workshop on Livelihoods and Languages took place in Bangkok, Thailand, from 9-11 April 2003. It was the first activity in a SPARK-STREAM learning and communications process around livelihoods and languages. (PDF contains 53 pages)
Resumo:
The Second SPARK-STREAM Workshop on Livelihoods and Languages took place in Tagaytay City, Philippines, from 12-14 June 2003. Outputs were intended to be: Drafts of language-specific “Guide to Learning and Communicating about Livelihoods”. Drafts of articles for STREAM Journal and SPARK Newsletter. Priorities and practical follow-up for capacity-building in carrying out participatory livelihoods analysis Follow-up plans. [PDF contains 30 pages]