[1] We examined data on 117 return strokes in 31 rocket‐and‐wire‐triggered lightning flashes acquired during experiments conducted from 1999 through 2004 at the International Center for Lightning Research and Testing at Camp Blanding, Florida, in order to compare the peak currents of the lightning return strokes with the corresponding charges transferred during various time intervals within 1 m...

Closed-form solutions were developed to optimize kinematics design of a 2-degree-of-freedom (2DOF) planar parallel manipulator. The optimum design based on the workspace was presented. Meanwhile, a global, comprehensive conditioning index was introduced to evaluate the kinematic designs. The optimal parallel manipulator is incorporated into a 5-DOF hybrid machine tool which includes a 2-DOF rot...

BACKGROUND Assessing the clinical effectiveness of measuring grip strength as a prognostic tool in recovering ambulation in bed-confined frail elderly patients. METHODS A prospective study was carried out with 50 elderly inpatients (mean age: 81.6 years old). Manual muscle test was used for checking strength of hip flexor muscles, hip abductor muscles and knee extensor muscles. Grip strength ...

[1] Lightning type identification of temporally coincident optical-VHF time series event pairs collected by the Fast On-orbit Recording of Transient Events (FORTE) satellite’s photodiode detector (PDD) and VHF instrument allows for the investigation of optical properties as a function of lightning type. General trends in the peak optical irradiance and characteristic pulse widths of PDD-VHF coi...

In this paper, the effect of ocean-land mixed propagation path on the lightning performance of grounding rods is investigated. This effect is focused on two problems. The first is extracting exact equivalent circuit of grounding rods in the presence of oceans. The equivalent circuit can be used in transient analysis of power systems in the neighboring oceans. In the second one, this effect on t...

Past and recent observations indicate the presence of lightning at altitudes in excess of 30 kin. The phenomenon is manifested as a high altitude optical flash, correlated with the presence of giant thunderstorms in the atmosphere below. This letter presents the first physical model of the process. The model is based on low frequency RF breakdown of the upper atmosphere, ignited by the upward p...

The conventional passive lightning protection mode depending on fixed lightning rods, overhead grounded wires, arresters and SPDs couldn’t fit for the demand in practice gradually. Therefore, it is necessary to explore an available and optional way that could enhance and improve them. Based on Intelligent Control Technology and combined with lightning detection, the Active Lightning Protection ...

Lightning has a profound impact on many aspects of modern day society. Understanding its spatial distributions is fundamental in learning to coexist with its tremendous power. This study examined the spatial distribution of cloud-to-ground lightning over southern Michigan using data provided by DTE Energy Corporation in Detroit, Michigan. Flash density and ‘lightning day’ maps were produced for...

This paper considers three interconnected problems: (i) initiation of a downward lightning in a thundercloud and that of an upward lightning near tall grounded structures; (ii) conditions for lightning development in the cloud-to-ground gap and the effects of lightning trajectory and branching on discharge parameters; and (iii) physical mechanism of the lightning return stroke and peculiarities...