The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Effects of Formic Acid on the Adsorption of Escherichia Coli

Adsorption of Escherichia coli K 88 on natural and acid-modified clinoptilolite was studied under ambient conditions. The materials under study were characterized in terms of surface area and cation-exchange capacity (CEC). Our study results indicate that treatment with formic acid can increase the Brunauer–Emmett–Teller (BET) surface area, CEC and adsorption capacity of clinoptilolite. The maximum adsorption on these non-metallic minerals was 25 mg/ml, beyond which the adsorption decreased as the amount of adsorptive increased. Time-dependent studies showed that the adsorption process reached equilibrium after 2 hours. The adsorption on E. coli K 88 increased with increasing concentration of the adsorption agent as well as with increasing concentration of the bacteria in suspension. The desorption of H + was studied by washing with a sterile physiological saline solution for 2 hours. The adsorption–desorption hysteresis suggests that the desorption rate of acid-modified clinoptilolite was much lower than that of natural clinoptilolite (P < 0.05). Acid modification of clinoptilolite increased the amount of bacterial adsorption due to the attractive interactions between the clinoptilolite and the bacteria. This increase may also involve the BET surface area and the surface characteristics of clinoptilolite

Herbicide-Resistance in Turf Systems: Insights and Options for Managing Complexity

Due to complex interactions between social and ecological systems, herbicide resistance has classic features of a “wicked problem.” Herbicide-resistant (HR) Poa annua poses a risk to sustainably managing U.S. turfgrass systems, but there is scant knowledge to guide its management. Six focus groups were conducted throughout the United States to gain understanding of socio-economic barriers to adopting herbicide-resistance management practices. Professionals from major turfgrass sectors (golf courses, sports fields, lawn care, and seed/sod production) were recruited as focus-group participants. Discussions emphasized challenges of the weed management of turfgrass systems as compared to agronomic crops. This included greater time constraints for managing weeds and more limited chemical control options. Lack of understanding about the proper use of compounds with different modes of action was identified as a threat to sustainable weed management. There were significant regional differences in perceptions of the existence, geographic scope, and social and ecological causes of HR in managing Poa annua. Effective resistance management will require tailoring chemical and non-chemical practices to the specific conditions of different turfgrass sectors and regions. Some participants thought it would be helpful to have multi-year resistance management programs that are both sector- and species-specific. © 2022 by the authors.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]