Nonequilibrium processes in meta-stable media⋆.

Meta-stable systems are those staying in the local equilibrium state: being slightly deviated from it they return to the equilibrium, but in case deviation surpasses a critical value those systems fall down to another equilibrium state. Chemically reacting gaseous mixture provides a typical example of a meta-stable system. The paper is aimed at numerical and experimental investigation of detonation initiation in hydrogen-air mixtures due to focusing of a shock wave reflected inside a wedge. Both numerical and experimental investigations were conducted. Comparison of numerical and experimental results made it possible to validate the developed 3D transient mathematical model of chemically reacting gas mixture flows incorporating hydrogen-air mixtures. Kinetic schemes and turbulence models were improved based on comparison of numerical and experimental results. Several different flow scenarios manifest in the reflection of shock waves all being dependent on the incident shock wave intensity: reflection of the shock wave with lagging behind the combustion zone, formation of a detonation wave in reflection and focusing, and intermediate transient regimes.

[Methods of isolating pure cultures of invasive intestinal helminth larvae of the genus Strongyloides, suborder Strongylata]. / Metodika izolace cistých kultur invazních larev strevních hlístic rodu Strongyloides a podrádu Strongylata.

A special diagnostic laboratory aid L-STAR has been made and new methodics has been worked out of isolating pure cultures of invader larvae of Strongyloides papillosus and nematodes of ruminant gastrointestinal tract of the Strongylata suborder from various substrates. L-STAR competes successfully with a currently used device and with potential modifications of Baermann's method (1917). Invader larvae of strongyloids and strongylata are easy to recover in a short time if L-STAR is used. When the material is treated and examined in veterinary and human parasitological laboratories, or when the material is recovered directly in field conditions (on pastures, in runs, etc.), safe and hygienic conditions are secured with respect to labour safety in an infectious environment. This aid can be used not only for diagnostics, but also for effective isolation of pure cultures of invader larvae for further studies and experimental purposes.

[The most important parasitic intestinal infections in calves and their role in diarrheal diseases]. / Nejdulezitejsí strevní parazitární nákazy telat a jejich role v etiologii prujmových onemocnení.

Various stock breeding herds in the USSR were examined for the presence of endoparasites. Coccidia of Cryptosporidium genus occurred in calves at the age of 3 to 4 days to one month, individually in older calves, too. Coccidia C. parvum infected the animals aged 14-15 days most frequently. Coccidia of Eimeria genus and intestinal round worm Strongyloides papilosus were registered sporadically in calves aged 13-15 days; most frequently they occurred in calves aged 1-2 months and older. Of the total number of the examined calves (aged 20 days), which were infected by Cryptosporidium, 77.7 resp. 89.8% were diarrhoeic. In cases of polyinfections with various species of coccidia of the Eimeria genus and S. papillosus, diarrhoea was recorded in 31.2% of one- to two-month-old calves. In cases of monoinfection with coccidia of the Eimeria genus diarrhoea was recorded in 15.8% of the calves, and in cases of infection with the intestinal worm S. Papillosus in 9.1% of the calves.