the paper presents the results of an investigation on the acoustic performance of vertical profile parallel barriers with quadratic residue diffuser tops and faces. a 2d boundary element method (bem) is used to predict the barrier insertion loss. the results of rigid and with absorptive coverage are also calculated for comparisons. using qrd on the top surface and faces of all vertical profile ...

environmental noise pollution is among the most urban problems which can be caused due to real sources like traffic, train and virtual sources provided by rigid surfaces. one of the urban structures in which can perform as a virtual noise source are the installed gutters alongside highways. these structures are mostly used to pass the wastewater or the rainfall. in this research, the acoustical...

the paper presents the results of an investigation on the acoustic performance of vertical profile parallel barriers with quadratic residue diffuser tops and faces. a 2d boundary element method (bem) was used to predict the barrier insertion loss. the results of rigid and with absorptive coverage were also calculated for comparisons. using qrd on the top surface and faces of all vertical profil...

Background Despite successful cloning of many mammalian species, the cloning efficiency is extremely low compared to that of IVF raising the possibility of the existence of epigenetic barrier preventing successful cloning. MaterialsAndMethods Using comparative transcriptome analysis comparing transcriptomes of IVF and SCNT embryos and that of donor cells, we identified epigenetic barrier and fi...

hexavalent chromium is mobile and hazardous in the environment. electrokinetic remediationof chromium (iv)-contaminated soils is intended either to remove or to reduce cr (vi) to cr (iii). this studyexamines the effectiveness of utilizing edta and acetic acid solutions as alternative electrolytes in theelectrokinetic (ek) process, with coupled nano-scale zero-valent iron (nzvi) as a barrier for...