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Numerical simulation of dilution effect on combustion and flame properties is desirable for various industrial or scientific applications. Predicative capabilities of the simplified (one- and two-step) chemical kinetic mechanisms of methane oxidation in highly diluted flames were evaluated on the basis of mathematical modelling in one-dimensional (axisymmetric) configuration. Profiles of temperatures and concentrations of reactants, combustion products and intermediates in premixed flat flame and nonpremixed counterflow flame burning methane and air/diluent mixture were determined. Detailed chemical kinetic modelling was performed additionally in order estimate the flame temperature and speciation and to quantify the effect of elevated argon and nitrogen concentration and oxygen deficiency on diluted combustion. Global chemical kinetic models were implemented into computational fluid dynamics tool to approve their applicability for numerical simulations of diluted flames in more complex geometries.

The nucleotide and predicted amino acid sequences of the coat protein coding region of four isolates (UK 1, CZE 1, CDN 1 and GK 1) and a putative mutant of one of these isolates (UK 1M) of turnip mosaic virus (TuMV) were determined. Comparisons between these and those of previously sequenced isolates showed homologies of 88.6–99.9% in nucleotides and 93.4–100% in amino acid sequences. Nucleotide substitutions were revealed at 180 different positions that give rise to 30 predicted amino acid changes. The coat protein coding regions consisted of 864 nucleotides, with the exception of GK 1 which had 861, having a deletion in amino acid position 44. This is the first recorded deletion in the coat protein coding region of TuMV. Alignment of the predicted amino acid sequences of UK 1, CZE 1, CDN 1 and GK 1 isolates with the previously sequenced CDN 2, CHN, JPN 1, JPN 2, JPN (31), L12396 and KOR isolates revealed three distinct groups which, with a few exceptions, were correlated with the geographical and/or host plant origin of isolates. The GK 1 isolate showed the lowest nucleotide (88.6–89.9%) and amino acid (93.4–96.2%) homologies with the other isolates, whereas the UK 1 isolate showed the highest nucleotide homology (89.7–99.9%) and CDN 1 showed the highest amino acid homology (95.9–99%). The coat protein coding region of the putative mutant isolate (UK 1M) had a single nucleotide difference (G to A) from UK 1 at position 9 which did not give rise to any change in the predicted amino acid sequence. UK 1M is able to infect Brassica napus plants possessing a mapped resistance gene ( TuRB01 ) that is effective against UK 1. The phenotypes of most of the sequenced isolates on plants containing TuRB01 are known, and these are consistent with the hypothesis that the single nucleotide substitution at position 9 of the coat protein coding region conditions the interaction with this gene. All isolates tested that had the residue G 9 gave no detectable replication in plants possessing TuRB01 , whereas isolates that had the residue A 9 were either partially virulent on plants carrying TuRB01 causing local infection only, or were fully virulent resulting in full systemic infection. This hypothesis is unprecedented in plant virus interactions and further experimentation utilizing full-length infectious clones of TuMV will be necessary to test its validity.

Pulsation frequency of the cup-burner flame was determined by means of experimental investigations and numerical simulations. Simplified chemical kinetics was successfully implemented into a laminar fluid flow model applied to the complex burner geometry. Our methodical approach is based on the monitoring of flame emission, fast Fourier transformation and reproduction of measured spectral features by numerical simulations. Qualitative agreement between experimental and predicted oscillatory behaviour was obtained by employing a two-step methane oxidation scheme.

The paper deals with the possibilities of modelling vapour propagation of explosive substances in the FLUENT software. With regard to very low tensions of explosive substance vapours the experiment has been verified as exemplified by mononitrotoluene. Either constant or time variable meteorological conditions have been used for calculation. Further, it has been verified that the eluent source may be time-dependent and may reflect a real situation or the liberation rate may be constant. The execution of the experiment as well as evaluation were clear and it could also be used for modelling vapour and aerosol propagation of selected explosive substances in the atmospheric boundary layer., {"references":["Dr├íbkov├í, s. Numerické modelov├ín├¡ neizotermn├¡ch turbulentn├¡ch\nproud┼». [doktorsk├í pr├íce]. Ostrava : fs v┼íb-tu, 2000. 140 p.","Kozubkov├í, m. Turbulence v atmosféře. Numerické modelov├ín├¡.\n[inaugural dissertation]. Ostrava : v┼íb-technical university of ostrava,\n2000. 119 p.","Stull, r.b. An introduction to boundary layer meteorology. Kluwer\nacademic publishers, 1994, 666 p.","Kozubkov├í, m. Modelov├ín├¡ proud─øn├¡ tekutin fluent, cfx. [cd-rom].\nOstrava : v┼íb-tu, 2008, 154 s. Isbn 978-80-248-1913-6.","Wiederlechner, j. Saliger, t. Monitoring of ammonia transport through\nthe atmosphere and possible impacts to the society. ðåv ð╝ðÁðÂð┤Ðâð¢ð░ÐÇð¥ð┤ð¢ð░\nð║ÐâÐÇÐüð░ð¢ÐéÐüð║ð¥-ÐüÐéÐâð┤ðÁð¢ÐéÐüð║ð░ ð¢ð░ÐâÐçð¢ð░ ð║ð¥ð¢ÐäðÁÐÇðÁð¢Ðåð©ÐÅ, veliko tarnovo,\nbulgaria 2008.","Zavila, o. Matematické modelov├ín├¡ turbulentn├¡ho proud─øn├¡, ┼í├¡řen├¡ tepla\na polutantu v mezn├¡ vrstv─ø atmosféry se zam─øřen├¡m na tunelové stavby.\n[dizerta─ìn├¡ pr├íce]. Ostrava : v┼íb - tuo, 2007. 114 p.","Ansys fluent inc. Fluent 12.16- user-s guide. [online]. C2009. Dostupné\nz: .","Bubn├¡k, j., keder, j.,macour, j., maň├ík, j. Metodick├¢ pokyn odboru\nochrany ovzdu┼í├¡ mžp v├¢po─ìtu zne─ìi┼ít─øn├¡ ovzdu┼í├¡ z bodov├¢ch a\nmobiln├¡ch zdroj┼» \"symos 97\" (systém modelov├ín├¡ stacion├írn├¡ch\nzdroj┼»). ─îhm├║ praha, ekoair praha 1999."]}