Laboratory anaerobic and aerobic digestion studies were conducted using waste activated sludges from two municipal wastewater treatment plants in order to gain insight into the mechanisms of floc ...destruction that account for changes in sludge conditioning and dewatering properties when sludges undergo anaerobic and aerobic digestion. Batch digestion studies were conducted at 20°C and the dewatering properties, solution biopolymer concentration and conditioning dose requirements measured. The data indicated that release of biopolymer from sludges occurred under both anaerobic and aerobic conditions but that the release was much greater under anaerobic conditions. In particular, the release of protein into solution was 4–5 times higher under anaerobic than under aerobic conditions. Both the dewatering rate, as characterized by the specific resistance to filtration and the amount of polymer conditioning chemicals required was found to depend directly on the amount of biopolymer (protein+polysaccharide) in solution. Little difference in dewatering properties and conditioning doses was seen between the two activated sludges from different plants. Differences in the cations released between anaerobic and aerobic digestion suggest that the digestion mechanisms differ for the two types of processes. Enyzme activity data showed that during aerobic digestion, polysaccharide degradation activity decreased to near zero and this was consistent with the accumulation of polysaccharides in aerobic digesters.
Measurements of the suppression of the yield per nucleon of J/psi and psi(') production for 800 GeV/ c protons incident on heavy nuclear targets, relative to light nuclear targets, have been made ...with very broad coverage in x(F) and p(T). The observed suppression is smallest at x(F) values of 0.25 and below, and increases at larger values of x(F). It is also strongest at small p(T). Substantial differences between psi(') and J/psi production are observed for the first time in p-A collisions. The suppression for psi(') production is stronger than that for J/psi for x(F) near zero, but becomes comparable to that for J/psi for x(F)>0.6.
We present measurements of the polarization of the J/psi produced in 800-GeV proton interactions with a copper target. Polarization of the J/psi is sensitive to the ccmacr; production and ...hadronization processes. A longitudinal polarization is observed at large x(F), while at small x(F) the state is produced essentially unpolarized or slightly transversely polarized. No significant variation of the polarization is observed versus p(T).
Existing determinations of the masses, widths and decay modes of low-lying excited states of the nucleon, as compiled in the Review of Particle Physics, are determined from energy-independent partial ...wave analyses of pion-nucleon scattering data. For the N*(1440) and most other resonances under 2 GeV, the analyses cited are the Karlsruhe-Helsinki, Carnegie Mellon-Berkeley and Kent State analyses, the latter of which used the elastic amplitudes from the other two. The data included in these analyses were published before 1980. Other analyses, notably the recent ones from George Washington University and the Pittsburgh-Argonne group, are "not used for averages, fits, limits, etc." Complete sets of measurements (differential cross sections, analyzing powers and spin rotation parameters) have been measured in the N*(1440) resonance region since 1980, culminating in the Crystal Ball program at BNL to measure all-neutral final states (charge exchange, multiple π0 final states, η production near threshold and inverse photoproduction). An overview of these data is presented and the case is made for a revitalized partial wave analysis effort
Data are presented for the reaction pi(-)p-->pi(0)pi(0)n in the range from threshold to p(pi(-))=750 MeV/c. The systematics of the data and multipole analyses are examined for sensitivity to a ...f(0)(600) ("sigma") meson. A one-pion-exchange mechanism is found to be very weak, or absent. The reaction appears to become dominated by sequential pi(0) decays through the Delta(1232) resonance as the beam momentum increases, along with substantial interference effects from several competing mechanisms.
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