On the sixth mechanism of lightning injury

A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree of Doctor of PhilosophyThe work presented in this thesis extends and contributes to research in the field of lightning injury mechanisms. Six mechanisms have been described in the literature about lightning injury. This thesis takes an in-depth look at the sixth injury mechanism. The sixth mechanism may be thought of as a ‘pressure-shock wave’ which is directly proportional to the current of the lightning discharge, and which is present immediately surrounding lightning’s luminous channel. A literature review, case studies and two novel experiments helped confirm the sixth mechanism’s existence. The medical data and the lightning data were then aligned. Two main questions were addressed, namely within what range is a human at risk; and what is the risk of lightning’s pressure shock wave. This ‘pressure-shock wave’ may explain some of the more curious lightning injury patterns seen on lightning-strike victims. Knowledge and insight into the sixth mechanism may have direct and indirect applications to those working in the fields of lightning injury and lightning protection. This thesis represents a contribution to the literature in both medicine and engineering

Delayed post mortem predation in lightning strike carcasses : sense or nonsense?

An adult giraffe was struck dead by lightning on a game farm outside Phalaborwa, South Africa in March 2014. Interestingly, delayed post-mortem predation occurred on the carcass, which according to the farm owners was an atypical phenomenon for the region. Delayed post-mortem scavenging on lightning strike carcasses has been anecdotally reported from time to time, although no formal studies have confirmed this phenomenon. The purpose of this article is to raise awareness of this phenomenon, with the view of more meticulous and scientific observations in future case studies.http://www.ajol.info/index.php/vulnew2015-07-3

Secondary missile injury from lightning strike

A 48 year-old-female was struck dead by lightning on the 24th October 2010 in Pretoria South Africa. The cause of death was due to direct lightning strike. Examination showed secondary missile injury on her legs. This secondary missile (shrapnel) injury was caused by the lightning striking the concrete pavement next to her. Small pieces of concrete were located embedded within the shrapnel wounds. This case report represents the first documented case of secondary missile formation (shrapnel injury) due to lightning strike in the literature.http://journals.lww.com/amjforensicmedicine/pages/default.asp

Injuries and deaths from lightning

This paper reviews recent academic research into the pathology of trauma of lightning. Lightning may injure or kill in a variety of different ways. Aimed at the trainee, or practicing pathologist, this paper provides a clinicopathological approach.http://jcp.bmj.comhj2021Forensic Medicin

Lightning medicine in South Africa

South Africa has a rich history of lightning research; however, research on the clinical and pathological effects and features of lightning-related injury (keraunomedicine or lightning medicine) remains neglected locally. By providing an overview of keraunomedicine and focussing on South African perspectives, we hope to raise awareness and propose that a concerted and co-ordinated attempt be made to report and collate data regarding lightning strike victims in South Africa.S Afr Med J 2012;102(7):625-62

Bone marrow embolism to the lung in electrocution : two case reports

Bone marrow embolism in electrocution was first described in the literature by Rappaport et al (Am J Pathol. 1951;27(3):407Y433) in 1951. Two case studies demonstrating this phenomenon are reported here, one involving high-voltage exposure with associated skeletal in-juries and the other involving domestic current and without evidence of skeletal injury. Both cases demonstrated bone marrow embolism on histologic examination of the lungs. The purposes of this article are to reiterate the existence of this unusual phenomenon and to consider possible pathogenetic mechanisms.http://journals.lww.com/amjforensicmedicine/pages/default.aspx2015-09-30hb201

Full-metal jacket mild steel core ammunition : a case report

The deceased was a 26-year-old man who was killed in a multiple shooting incident while sitting alone in his car. This individual was shot by multiple individuals, with different types of ammunition, from different angles. It is beyond the scope of this article to describe all the gunshot wounds. It is the intention of the authors to merely focus on the pathology of trauma of full-metal jacket ammunition with a penetrator (mild steel core in this presentation). The authors describe what was found at autopsy.https://journals.lww.com/amjforensicmedicine/Pages/aboutthejournal.aspxhj2024Forensic MedicineNon

Fundamental noise dynamics in cascaded-order Brillouin lasers

The dynamics of cascaded-order Brillouin lasers make them ideal for applications such as rotation sensing, highly coherent optical communications, and low-noise microwave signal synthesis. Remark- ably, when implemented at the chip-scale, recent experimental studies have revealed that Brillouin lasers can operate in the fundamental linewidth regime where optomechanical and quantum noise sources dominate. To explore new opportunities for enhanced performance, we formulate a simple model to describe the physics of cascaded Brillouin lasers based on the coupled mode dynamics governed by electrostriction and the fluctuation-dissipation theorem. From this model, we obtain analytical formulas describing the steady state power evolution and accompanying noise properties, including expressions for phase noise, relative intensity noise and power spectra for beat notes of cascaded laser orders. Our analysis reveals that cascading modifies the dynamics of intermediate laser orders, yielding noise properties that differ from single-mode Brillouin lasers. These modifications lead to a Stokes order linewidth dependency on the coupled order dynamics and a broader linewidth than that predicted with previous single order theories. We also derive a simple analytical expression for the higher order beat notes that enables calculation of the Stokes linewidth based on only the relative measured powers between orders instead of absolute parameters, yielding a method to measure cascaded order linewidth as well as a prediction for sub-Hz operation. We validate our results using stochastic numerical simulations of the cascaded laser dynamics.Comment: 18 pages, 9 figure