The PHENIX experiment at RHIC has measured transverse energy and charged particle multiplicity at mid-rapidity in Au + Au collisions at √ s N N = 19.6, 130 and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments, and experiments at lower energies. The √ s N N dependence of dET /dη and dN ch /dη per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of dET /dη and dN ch /dη is similar at all measured incident energies. At RHIC energies the ratio of transverse energy per charged particle was found independent of centrality and growing slowly with √ s N N . A survey of comparisons between the data and available theoretical models is also presented.

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A series of unsaturated column experiments was conducted to study different grain-scale accumulation mechanisms affecting total uptake of volatile organic compounds (VOCs) onto a model solid and subsequent removal of VOCs from the porous media. Experimental variables included VOC (benzene, methylbenzene, 1,4-dimethylbenzene, and 1,3,5-trimethylbenzene), moisture content (primarily water-unsaturated conditions), and influent VOC concentration. Calculations of the mass distributions of benzene indicated that it was primarily in the aqueous and air phases with a small fraction at the airwater interface. Similar calculations for the other VOCs indicated that greater than 50% of the accumulated mass of these VOCs was located within intraparticle pores and on the substrate surface. Analysis of the sorption data in terms of a pore-filling model support the hypothesis that a capillary phase separation (CPS) process occurred within the pores and produced a neat, separate VOC phase. We suggest that CPS will become more critical in materials with small mesopores or micropores, and that it is partly responsible for the existence of a resistant fraction of VOCs present within water-filled intraparticle pores.

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