Comparative metagenomics approaches to characterize the soil fungal communities of western coastal region, Saudi Arabia

A total of 145007 reads were obtained from pyrosequencing for all the 4 samples. The total count ranged from 11,301,014 (Mecca old road) to 23,503,512 bp (Thuwal). A total of 460 fungal species belonging to 133 genera, 58 families, 33 orders, 13 classes and 4 phyla was identified across the four sites. The most abundant phylum at all four sites was Ascomycota followed by Basidiomycota. Four phyla (Ascomycota-99.31%, Basidiomycota-0.59%, Chytridiomycota-0.04%, Glomeromycota-0.03%) were detected in Khulais. Except for Glomeromycota, all phyla were detected at Mecca old road (Ascomycota-74.26%, Basidiomycota-25.71%, Chytridiomycota-0.01%) and Thuwal (Ascomycota-99.59%, Basidiomycota-0.40%, Chytridiomycota-0.002%); while only Ascomycota-90.98% and Basidiomycota-9.01% were detected in Asfan road. At the class level, Sordariomycetes was predominantly observed at Asfan road-59.88%, Khulais-68.26% and Thuwal-94.84%; while Pezizomycetes was dominant at Mecca old road-56.01%, was absent at Asfan road. Agaricomycetes was present only at Mecca old road-25.73%; while Tremellomycetes-5.77%, Malasseizomycetes-2.13% and Microbotryomycetes-1.10% were found only at Asfan road. The phylogenetic trees revealed that clear genus level differences are visible across all the four sites, with an overall predominance of Thielavia followed by Madurella, Aspergillus, and Gelasinospora. Chaetomium sp., Aspergillus caespitosus and Aspergillus sp. were found in moderate (Mecca old road and Thuwal) to abundant (Asfan road and Khulais) quantities. Thielavia sp., Thielavia hyalocarpa and Madurella sp. are found in moderate quantities at Khulais and Mecca old road, while in abundant levels at Asfan road and Thuwal. Fusarium equisati and F. oxysporum were detected at Thuwal and Khulais. Sordaria araneosa was present at Khulais, while Malasseiza globosa species was detected in moderate quantities across all sites except Khulais

Numerical prediction of shock/boundary-layer interactions at high Mach numbers using a modified Spalart–Allmaras model

The Reynolds-averaged Navier–Stokes equations with one-equation turbulence models are used to simulate the flow field past a cone–flare geometry in the Mach number range from 5 to 8 with emphasis on the interaction region of the flare shock with the upstream boundary layer. A model based on the physics of shock unsteadiness is used to correct the standard Spalart–Allmaras turbulence model to improve the prediction of the extent of the separation bubble arising from the shock/turbulent boundary-layer interaction and its accompanying peak pressure and aerothermal loads on the surface. The computed results are validated against the experimental data. The limitations of the shock-unsteadiness model and the extent of the improvement in predicting the heat flux are discussed