Modification of Amberlite XAD-2 resin for U(VI) adsorption from Egyptian crude phosphoric acid

Adsorption of U(VI) from Egyptian crude phosphoric acid was studied using the modified Amberlite XAD-2 resin. Modification process was performed by soaking Amberlite XAD-2 resin in tri-butyl phosphate (TBP) and di-2-ethyl hexyl phosphoric acid (D2EHPA) for increasing its adsorption capacity via equilibrium batch technique. For this purpose, different effective parameters such as: a dose of adsorbent, contact time, temperature, phosphoric acid concentration, and initial uranium (VI) concentration were investigated. The maximum sorption capacity by the modified resin achieved 67 mg g−1 of U (VI). Sorption of U (VI) follows both the Langmuir and Freundlich adsorption isotherms. Not less than 93% of the U (VI) uptaken by the modified Amberlite XAD-2 resin was desorbed using 1 mol L−1 NaCl + 0.1 mol L−1 H2SO4. Keywords: Uranium (VI), Amberlite XAD-2, Tri-butyl phosphate (TBP), Di-2-ethyl hexyl phosphoric acid (D2EHPA), Phosphoric aci

Impact of major design parameters on the economics of Tokamak power plants

A parametric systems studies program is now in an active stage at Argonne National Laboratory. This paper presents a summary of results from this systems analysis effort. The impact of major design parameters on the economics of tokamak power plants is examined. The major parameters considered are: (1) the plant power rating; (2) toroidal-field strength; (3) plasma ..beta../sub t/; (4) aspect ratio; (5) plasma elongation; (6) inner blanket/shield thickness; and (7) neutron wall load. The performance characteristics and economics of tokamak power plants are also compared for two structural materials (stainless steel and a vanadium alloy)

Assessment of the presence of Salmonella spp. in Egyptian dairy products using various detection media

Aims: To make a preliminary assessment of the incidence of Salmonella in Egyptian dairy products, and to investigate the effectiveness of various protocols for the detection of the pathogen in these products. Methods and Results: Samples of milk and related dairy products were randomly collected from local markets and examined for the presence of Salmonella. While most samples were free of the organism, isolates of Salmonella enterica subsp. enterica serovar Typhimurium PT 8 could be recovered from 'matared' cream specimens. These isolates were susceptible to antibiotics usually used to challenge infections caused by Salmonella. A combination of buffered peptone water, Muller-Kauffman tetrathionate broth, and brilliant green phenol red agar gave the best results for the detection of the pathogen. Selenite-cystine broth and Hektoen enteric agar were ineffective as an enrichment and a plating medium, respectively, in the isolation of Salmonella. A modified identification strategy that reduces the burden of serological testing of presumptive isolates is proposed. Conclusions, Significance and Impact of the Study: 'Matared' cream could be a vehicle for transmitting Salmonella. Using the above combination of media, beside the suggested modified confirmatory procedure, should increase the effectiveness and ease of the detection of Salmonella in milk and dairy products