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Chromosome pairing in Loloium perenne x L. temulentum diploid hybrids is discussed with genetic and cytogenetic evaluation. One genotype was selected for low chiasma frequency over numerous generations and was thought to contain one or two heterozygous dominant genes with a significant effect on chiasma frequency. Findings indicate control of paired-arm (PA) frequency in E5/2/5/10 was not a simple genetic mechanism.

Studying vaporization of binary mixture liquid droplets as a model system provides useful information for understanding several engineering applications involving multicomponent systems. The present study investigated vaporization behaviour of both polar and non-polar binary droplet systems in hot convective environment using a mathematical model and experiments. A lumped parameter rapid mixing evaporation model accounting for non-ideal solution behaviour and temperature dependent physical properties was presented. The model predicted temporal variation in droplet diameter and temperature were validated against the experimental data for heptane-decane and water-glycerol mixture. Experiments involving the water-glycerol system involved both size and temperature measurement of millimetre-size droplets at constant gas temperature ∼353 K and at free stream gas velocity ∼4.3 m/s. In general, model predictions were in good agreement with the experiments however some deviations in the model prediction were noted at the transition stage specifically for the water-glycerol system which was attributed to the liquid phase diffusional resistance not accounted in the present modelling framework. Inclusion of activity coefficient into the model was shown to have insignificant effect on the evaporation rate in both non-polar and polar systems. Internal motions induced by the external shear flow and internal density difference were quantified. Time scales based on heat transfer (convective heat transfer and thermal diffusion) and mass diffusion accounting for the internal motion were estimated. It was shown that the unsteady heating duration of the droplet fall within the two limits set by the heat transfer and mass diffusion time scales. [ABSTRACT FROM AUTHOR]

Detached eddy simulation (DES) of the liquid-phase turbulent flow in an unbaffled stirred tank agitated by a six-blade, 45°-pitched blade turbine was performed in this study. The tank wall is cylindrical with no baffle and the fluid flow problem was solved in a single reference frame (SRF) rotating with the impeller. For the purpose of comparison, computation based on large eddy simulation (LES) was also carried out. The commercial code Fluent was used for all simulations. Predictions of the phase-averaged turbulent flow quantities and power consumption were conducted. Results obtained by DES were compared with experimental laser Doppler velocimetry (LDV) data from the literature and with the predictions obtained by LES. It was found that numerical results of mean velocity and turbulent kinetic energy profiles as well as the power consumption are in good agreement with the LDV data. When performed on the same computational grid, which is under-resolved in the sense of LES, DES allows better accuracy than LES in that it works better in the boundary layers on the surface of the impeller and the stirred tank walls. It can be concluded that DES has the potential to predict accurately the turbulent flow in stirred tanks and can be used as an effective tool to study the hydrodynamics in stirred tanks. [ABSTRACT FROM AUTHOR]