The Olympic flame and torch are significant symbols of the Olympic Games and are important in linking the general public with the festival. They are internationally recognized symbols, particularly important at the Opening and Closing Ceremonies. “It is through the opening and closing ceremonies and the torch relay that the Olympiad must distinguish itself from another series of world champions...

A retrospective analysis was conducted on air samples that were collected in 2005 under the Global Atmospheric Passive Sampling (GAPS) Network around the time period when the Stockholm Convention on Persistent Organic Pollutants came into force. Results are presented for several new flame retardants, including hexabromocyclododecane (HBCD), which was recently listed under the Convention (2013)....

In previous studies, we examined turbulence-flame interactions in carbonburning thermonuclear flames in Type Ia supernovae. In this study, we consider turbulence-flame interactions in the trailing oxygen flames. The two aims of the paper are to examine the response of the inductive oxygen flame to intense levels of turbulence, and to explore the possibility of transition to detonation in the ox...

A computational study has been conducted to determine the critical conditions for the transition from localized flame ignition and propagation to the establishment of a flame ball. Lean H2/air mixtures are investigated using a time-dependent, spherically symmetric code with detailed chemistry, transport, and radiation submodels. Results show that outwardly propagating spherical flames can be ig...

In this thesis, thermal-diffusive instabilities are studied experimentally in diffusion flames. The novel species injector of a recently developed research burner, consisting of an array of hypodermic needles, which allows to produce quasi one-dimensional unstrained diffusion flames has been improved. It is used in a new symmetric design with fuel and oxidizer injected through needle arrays whi...

Cultural heritage and archaeological sites are exposed to the risk of fire and early warning is the only way to avoid losses and damages. The use of terrestrial systems, typically based on video cameras, is currently the most promising solution for advanced automatic wildfire surveillance and monitoring. Video cameras are sensitive in visible spectra and can be used either for flame or smoke de...

Thrust and fire safety are among NASA’s major concerns in the fulfillment of its mission on Mars Exploration, especially the missions that planned to bring astronauts to and back from the Red Planet. Responding to these concerns, the research studied the burning characteristics and extinction of diffusion flames in space, which are different from those on Earth due to the lack of gravity. Becau...

Using X-ray crystallography to visualize the three-dimensional structure of an enzyme associated with regulating levels of estrogen, a team of National Institutes of Health scientists have discovered new information on how flame retardants may alter estrogen metabolism. Their results suggest one way in which these chemicals may disrupt the body’s endocrine system. Flame retardants are added to ...

In this paper we study the behavior of a premixed turbulent methane flame in three dimensions using numerical simulation. The simulations are performed using an adaptive time-dependent low Mach number combustion algorithm based on a second-order projection formulation that conserves both species mass and total enthalpy. The species and enthalpy equations are treated using an operator-split appr...

A dominant factor in determining the burning rate of a premixed turbulent flame is the degree to which the flame front is wrinkled by turbulence. Higher turbulent intensities lead to greater wrinkling of the flame front and an increase in the turbulent burning rate. This picture of turbulent flame dynamics must be modified, however, to accommodate the affects of variations in the local propagat...