background & aims of the study: heavy metals contaminate drinking water, air and soils. it is very harmful for humans and other live organisms. phytoremediation is one of the direct bio-remediation methods for heavy metal removal from polluted water and soils. this method is accepted environmentally, economically and aesthetically. the purpose of this study was to assess tamarix hispida capacit...

Direct numerical simulation data of a 24 compression ramp configuration are used to analyze the shock motion. The characteristic frequencies in the incoming boundary layer are reported for reference. The shock wave motion exhibits high-frequency spanwise wrinkling, as well as low-frequency streamwise motion. Correlations between the incoming flow and the shock motions, as well as the downstream...

Department of Environmental and Biomolecular Systems, Oregon Health and Science University, Beaverton, Oregon 97006, USA; Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon 97201, USA; Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA; Department of Microbiology and De...

Cementing systems using ultra-lightweight hollow spheres can improve lightweight cement performance in deepwater operations and provide a viable alternative to conventional lightweight cement slurries. Efforts to expand the temperature limits of MWD and LWD tools have seen limited success. New approaches may be necessary if industry is to meet the demand for gas from deep reservoirs. Mixing fra...

It is often claimed that large buyers wield buyer power. Existing theories of this effect generally assume upstream monopoly. Yet the evidence is strongest with upstream competition. We show that upstream competition can yield buyer power for large buyers by generating supplier-level volume uncertainty—a feature that emerges from case study evidence of upstream competition—so the negotiated pri...

background: this study was carried out to determination of heavy metals (cd, cr, cu, fe, pb, ni and zn) concentration in upstream and downstream of the entry of the wastewater (untreated urban, traditional slaughterhouse waste, leachate from solid wastes has accumulated in river and  run off waters flowing across the city ) to the tembi river. methods: samples were collected for 1 year, before ...

This chapter examines the tradeoffs of regulating upstream (e.g., coal, natural gas, and refined petroleum product producers) versus regulating downstream (e.g., direct sources of greenhouse gases (GHG)). In general, regulating at the source provides polluters with incentives to choose among more opportunities to abate pollution. This chapter develops a simple theoretical model that shows why t...