Numerical simulation of soot optical diagnostics in non-optically thin media

The global aim of this paper consists of quantifying the effect of optically thick media on LII measurements. The paper emphasises in a simple, general two-phase case, the potential “signal trapping” due to the multiple scattering of light by soot particles. A statistical Monte Carlo approach has been used in the frame of a parametric study. This method allows testing separately the distinct influences of parameters like soot volume fraction, sphere diameter, optical path length or aggregate shape. As a first result of this numerical study, the theoretical validity range of experimental techniques can be determined when applied to a larger domain than the strictly optically thin one. A numerical tool for a better understanding of mixed and complex phenomena has been realised. Here the approach is validated on the simplest geometrical configuration; it will be applied to a real combustion chamber configuration later. PACS 78.70.-g     

Who wants to break the hockey-stick sales pattern in the supply chain?

The hockey-stick pattern faced by suppliers consists of sales spikes at the end of each period. One of its causes is the information asymmetry that favors the retailer, who has better knowledge about the stochastic consumer demand. Because of delayed purchases, the supplier is induced to offer promotions, allowing the retailer to forward-buy at low prices. We model this situation as an infinitely repeated game, where each stage-game is subject to imperfect information. Drawing from the Nash equilibrium, we express sales and inventories in terms of demand, cost and the strategies players may adopt, and derive the conditions for a cooperative equilibrium.     

Reaction of azoxyanisole with oxalyl chloride: use of photoelectron spectroscopy in seeking new reactions

Azoxyanisole, but not azoxybenzene, reacts readily with oxalyl chloride to give the corresponding orth-substituted azocompound. The differences in reactivity are discussed in terms of different HOMO energies, measured by PES.     

Absolute Configuration of a Diterpene Lactone from Parinari capensis

Phytochemical investigation of Parinari capensis (Chrysobalanaceae) led to the isolation of three diterpene lactones 1–3. The structures of these compounds have been established by NMR spectroscopy and X-ray crystal-structure analysis. Addition of bromine onto the exocyclic methylidene group of 1 yielded the brominated derivative 1-Br . X-Ray analysis of 1-Br established unambiguously the absolute configuration, and 1 was then identified as the (4R, 9R)-10-hydroxy-13-methoxy-9-methyl-15-oxo-20-norkaur-16-en-18-oic acid γ-lactone. Diterpenes 2 and 3 were identified as the C(13)-demethoxylated and the C(13)-demethylated derivatives of diterpene 1 , respectively. Antifungal activity against Cladosporium cucumerinum was determined for 1–3 .