Search

Mars Sample Return (MSR) architecture and mission engineering, led by Boeing for JPL, is presented. The study sought credible data to support planning a 2011 mission to return 500g of scientifically selected samples.Phase 1 compared diverse architecture options to accomplish the mission. 17 theme-based architectures were conceived, quantified, measured, and scored. Two primary and three secondary architectures were recommended.Phase 2 developed engineering detail for a simple architecture specified by JPL: dual mission to two landing sites; short-range, radioisotope-powered sampling rovers; Mars orbit rendezvous; and electric return propulsion with Shuttle rendezvous. The design comprises nine system elements. Solutions for sample handling and breaking the back contamination chain are detailed. Total mission duration is five years.Technology tailoring, rather than technology creation, is required. Mission development cost, including margins and wraps, is $2.8B. The study concluded that many schemes can feasibly accomplish Mars sample return, depending on program objectives adopted. [Copyright &y& Elsevier]

The development of innovative antimicrobial materials is crucial in thwarting infectious diseases caused by microbes, as drug-resistant pathogens are increasing in both number and capacity to detoxify the antimicrobial drugs used today. An ideal antimicrobial material should inhibit a wide variety of bacteria in a short period of time, be less or not toxic to normal cells, and the fabrication or synthesis process should be cheap and easy. We report a one-step microwave-assisted hydrothermal synthesis of mixed composite Cu x Fe y O z (Fe 2 O 3 /Cu 2 O/CuO/CuFe 2 O) nanoparticles (NPs) as an excellent antimicrobial material. The 1 mg/mL Cu x Fe y O z NPs with the composition 36% CuFeO 2 , 28% Cu 2 O and 36% Fe 2 O 3 have a general antimicrobial activity greater than 5 log reduction within 4 h against nine important human pathogenic bacteria (including drug-resistant bacteria as well as Gram-positive and Gram-negative strains). For example, they induced a >9 log reduction in Escherichia coli B viability after 15 min of incubation, and an ~8 log reduction in multidrug-resistant Klebsiella pneumoniae after 4 h incubation. Cytotoxicity tests against mouse fibroblast cells showed about 74% viability when exposed to 1 mg/mL Cu x Fe y O z NPs for 24 h, compared to the 20% viability for 1 mg/mL pure Cu 2 O NPs synthesized by the same method. These results show that the Cu x Fe y O z composite NPs are a highly efficient, low-toxicity and cheap antimicrobial material that has promising potential for applications in medical and food safety.