Buoyant unstable behavior in initially spherical lean hydrogen-air premixed flames within a center-ignited combustion vessel have been studied experimentally under a wide range of pressures (including reduced, normal, and elevated pressures). The experimental observations show that the flame front of lean hydrogen-air premixed flames will not give rise to the phenomenon of cellular instability ...

Fermentation in the large bowel has been postulated to play a protective role against colon cancer. Hydrogen and methane are end products of this fermentation process and are absorbed into the bloodstream and excreted via expired air in the breath. Breath levels of hydrogen and, to a lesser extent, methane correlate strongly with colonic fermentation and may serve as useful biomarkers for this ...

Concentration of oxygen, methane, and hydrogen were measured in intracolonic gas samples aspirated through the colonoscope at the time of colonoscopy from 46 patients. Of the above patients 20 prepared either with mannitol (n = 10) or with castor oil (n = 10) had the instrument passed to the caecum without air insufflation or suction. After mannitol, mean intracolonic hydrogen concentration (4....

In order to evaluate the performance of biofilter for H2S removal from contaminated air, a 120×14 cm column biofilter was constructed using clear polyacrylic material in conjunction with H2S production and control systems. The column was divided into four stages using perforated plates. The column was packed with a mixture of mushroom compost and snail shell (4:1). The performance of biofilte...

The hydrogen breath test was performed by ingestion of 20 g lactulose and analysis of end-expiratory air. Eighteen patients undergoing colonoscopy, 17 receiving antibiotics, 12 prepared for colon surgery, and 15 controls were examined. The test was repeated under control conditions in the treated patients. Eleven of 55 subjects failed to produce significant amounts of hydrogen under control con...

Thermodynamic parameters of the hydriding reaction of a hydride electrode can be obtained by two different methods. The results show that the change of enthalpy AH, change of entropy AS and hydrogen pressure calculated from e-c-T curves of electrochemical reactions have much larger inherent errors compared with those obtained from p-c-T curves of alloys in hydriding reactions with hydrogen gas ...

Hydrogen in metal oxides usually strongly associates with a neighboring oxygen ion through an O-H bond and thus displays a high stability. Here we report a novel state of hydrogen with unusually high mobility and reactivity in metal oxides at room temperature. We show that freshly doped hydrogen in Nb₂O₅ and WO₃ polycrystals via electrochemical hydrogenation can reduce Cu²⁺ ions into Cu⁰ if the...

Exhaled air condensate provides a noninvasive means of obtaining samples from the lower respiratory tract. Hydrogen peroxide (H2O2) in exhaled air has been proposed as a marker of airway inflammation. We hypothesized that in stable asthmatic children the H2O2 concentration in exhaled air condensate may be elevated as a result of airway inflammation. In a cross-sectional study, 66 allergic asthm...

This dissertation: (i) develops a novel numerical method for DNS/LES of compressible, turbulent reacting flows, (ii) performs several validation simulations, (iii) studies auto–ignition of a hydrogen vortex ring in air and (iv) studies a hydrogen/air turbulent diffusion flame. The numerical method is spatially non-dissipative, implicit and applicable over a range of Mach numbers. The compressib...