Results 251 to 260 of about 2,311,006 (294)

Properties of preliminary breakdown processes in Scandinavian lightning

Journal of Atmospheric and Solar-Terrestrial Physics, 2008
Lightning flashes are usually preceded by preliminary breakdown processes (PBPs) before a stepped leader is initiated. These breakdown processes are not well understood. An early model, the so-called BIL model, has been called into question in later studies.
J. Makela, N. Porjo, A. Mäkelä, T. Tuomi, V. Cooray   +4 more
semanticscholar   +2 more sources

Preliminary breakdown, following lightning discharge processes and lower positive charge region

Atmospheric Research, 2015
Abstract Bipolar pulse trains in wideband electric field records are often attributed to preliminary breakdown (PB) processes (Nag and Rakov, 2009). Using electric field waveforms of lightning discharges observed in Beijing and Guangzhou, the detectable PB pulses and the following discharges are analyzed, and the role of lower positive charge region (
Yang Zhang, Yijun Zhang, D. Zheng, Weitao Lu   +3 more
semanticscholar   +2 more sources

Comparative study on preliminary breakdown pulse trains observed in Malaysia and Florida

2010 30th International Conference on Lightning Protection (ICLP), 2010
In this paper, the preliminary breakdown pulse (PBP) trains preceding the negative first return strokes recorded using a broad band antenna system in Johor Bahru, Malaysia and Florida, United States were analyzed. In lightning flashes observed in Malaysia, the ratio between the amplitude of the largest preliminary breakdown pulse (PBP) and the peak ...
Z. A. Baharudin, N. A. Ahmad, M. Fernando, V. Cooray, J. Mäkelä   +4 more
semanticscholar   +2 more sources

Comparison of preliminary breakdown pulses observed in Sweden and in Sri Lanka

Journal of Atmospheric and Solar-Terrestrial Physics, 1998
Abstract In this paper we have analysed breakdown pulse trains preceding the first return stroke in 47 negative cloud-to-ground (CG) lightning flashes observed in Sri Lanka (tropics) and that in 41 negative CG flashes recorded in Sweden (temperate regions). In the data obtained in Sri Lanka, breakdown pulses could be detected only in nine flashes. In
C. Gomes, V. Cooray, Chandana Jayaratne
semanticscholar   +2 more sources

Correlation analysis of preliminary breakdown and first return stroke process in negative ground flash as a function of Northeast and Southwest monsoon in tropic

Journal of Engineering and Applied Sciences (Asian Research Publishing Network), 2023
The separation duration of Preliminary Breakdown to the First Return Stroke (PB-RS duration) and the ratio between the highest amplitude pulse of Preliminary Breakdown and the first Return Stroke pulse (PB/RS ratio) were successfully used as a tool by ...

semanticscholar   +1 more source

Microchip Laser-Induced Breakdown Spectroscopy: A Preliminary Feasibility Investigation

Applied Spectroscopy, 2004
A commercial, 7 μJ/pulse, 550 ps microchip laser is used to induce plasma on Pb, Si, Cu, Fe, Ni, Ti, Zn, Ta, and Mo foils and a Si wafer. The measured plasma lifetime is comparable with the duration of the laser pulse (a few ns). The plasma continuum radiation is low, while some of the strong resonance lines (e.g., Zn 213.86 nm) show self-reversal ...
I B, Gornushkin, K, Amponsah-Manager, B W, Smith, N, Omenetto, J D, Winefordner   +4 more
openaire   +2 more sources

Initial Leader Properties During the Preliminary Breakdown Processes of Lightning Flashes and Their Associations With Initiation Positions

Journal of Geophysical Research: Atmospheres, 2019
The properties of initial leaders (ILs) of 1,056 flashes in two thunderstorms in Guangzhou, China, are analyzed. The median values of IL properties are 11.1 ms for duration, 2.2 km for vertical distance, 2.7 km for 3‐D distance, 1.9 × 105 m/s for ...
D. Zheng, D. Shi, Yang Zhang, Yijun Zhang, W. Lyu, Q. Meng   +5 more
semanticscholar   +1 more source

Preliminary evaluation of laser induced breakdown spectroscopy for slurry samples

Spectrochimica Acta Part B: Atomic Spectroscopy, 2009
Abstract Laser-induced breakdown spectroscopy (LIBS) was applied to the analysis of simulant slurry samples used in the vitrification process of liquid radioactive wastes. A spectroscopic analysis was performed by two different detection systems: Czerny-Turner spectrometer coupled with intensified diode array detector (IDAD) and an Echelle ...
Seong Yong Oh, Fang Yu Yueh, Jagdish P. Singh, Connie C. Herman, Kristine Zeigler   +4 more
openaire   +1 more source

KARAKTERISTIK PRELIMINARY BREAKDOWN PETIR TERMINOLOGI BREAKDOWN-LEADER (BL) SEBELUM SAMBARAN NEGATIF PERTAMA [PDF]

, 2015
Latar Belakang Kota Padang merupakan salah satu daerah yang memiliki potensi cukup besar dalam kejadian petir setiap tahunnya. Hal ini karena kota Padang secara geografis terletak disekitar garis ekuator dan mendapatkan intensitas cahaya matahari yang merata sepanjang tahunnya.
openaire   +1 more source

Preliminary evaluation of laser-induced breakdown spectroscopy for tissue classification

Spectrochimica Acta Part B: Atomic Spectroscopy, 2009
Laser-induced breakdown spectroscopy (LIBS) is an on-line, real-time technology that can produce immediate information about the elemental contents of tissue samples. We have previously shown that LIBS may be used to distinguish cancerous from non-cancerous tissue.
Fang-Yu Yueh, Hongbo Zheng, Jagdish P. Singh, Shane Burgess   +3 more
openaire   +1 more source