825 research outputs found
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Plastic Microbial Acclimation and Optimisation of Composting and Anaerobic Digestion Processes may Improve Degradation Times
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Greenhouse gas emissions from non-recyclable residual household waste within domestic wheeled bins
The evolution of greenhouse gases (GHGs) from waste treatment processes (e.g. landfill & composting) are well documented (Chen and Lin, 2008), frequently quantified (Lou and Nair, 2009) and currently represented within climate change models (Ciais et al., 2013). Conversely, the understanding of GHG emissions from household waste (pre-collection) is largely unknown and confined to composting studies (e.g. Andersen et al., 2010), or calculating the calorific value/elemental content (Komilis et al., 2012) and biological methane potential (Alibardi and Cossu, 2015) of municipal solid waste. Generating a better understanding of GHG fluxes from non-recycled residual household waste before collection may help to further refine climate models and inform policy makers regarding the best collection strategy to mitigate GHG emissions
Methane emissions from forested closed landfill sites: Variations between tree species and landfill management practices
Trees in natural and managed environments can act as conduits for the transportation of methane (CH4) from below ground to the atmosphere, bypassing oxidation in aerobic surface soils. Tree stem emissions from landfill sites exhibit large temporal and spatial variability in temperate environments and can account for approximately 40% of the total surface CH4 flux. Emission variability was further investigated in this study by measuring CH4 and CO2 fluxes from landfill sites with different management strategies and varying tree species over a 7-month period. Stem and soil measurements were obtained using flux chambers and an off-axis integrated cavity output spectroscopy analyser. Analysis showed average stem and soil CH emissions varied significantly (p4 fluxes from sites with no clay cap but gas extraction, clay cap and gas extraction, and no clay cap and no gas extraction were 1.4 ± 0.4 μg m-2 h-1, 47.2 ± 19.0 μg m-2 h-1, and 111.9 ± 165.1 μg m-2 h-1, respectively. There was no difference in stem CH4 fluxes between species at each site, suggesting environmental conditions (waterlogging) and site age had a greater influence on both stem and soil fluxes. These results highlight the importance of management practices, and the resultant environmental conditions, in determining CH4 emissions from historic landfill sites
Observation of the Dynamic Beta Effect at CESR with CLEO
Using the silicon strip detector of the CLEO experiment operating at the
Cornell Electron-positron Storage Ring (CESR), we have observed that the
horizontal size of the luminous region decreases in the presence of the
beam-beam interaction from what is expected without the beam-beam interaction.
The dependence on the bunch current agrees with the prediction of the dynamic
beta effect. This is the first direct observation of the effect.Comment: 9 page uuencoded postscript file, postscritp file also available
through http://w4.lns.cornell.edu/public/CLNS, submitted to Phys. Rev.
Rate Measurement of and Constraints on Mixing
We present an observation and rate measurement of the decay D0 -> K+pi-pi0
produced in 9/fb of e+e- collisions near the Upsilon(4S) resonance. The signal
is inconsistent with an upward fluctuation of the background by 4.9 standard
deviations. We measured the rate of D0 -> K+pi-pi0 normalized to the rate of
D0bar -> K+pi-pi0 to be 0.0043 +0.0011 -0.0010 (stat) +/- 0.0007 (syst). This
decay can be produced by doubly-Cabibbo-suppressed decays or by the D0 evolving
into a D0bar through mixing, followed by a Cabibbo-favored decay to K+pi-pi0.
We also found the CP asymmetry A=(8 +25 -22)% to be consistent with zero.Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Study of 3-prong Hadronic Decays with Charged Kaons
Using a sample of 4.7/fb integrated luminosity accumulated with the CLEO-II
detector at the Cornell Electron Storage Ring (CESR), we have measured the
branching fractions of the tau lepton into and relative to and relative to . The relative branching fractions are: (5.16+-0.20+-0.50)*,
(1.52+-0.14+-0.29)*, (2.54+-0.44+-0.39)* and at 95%
C.L., respectively. Coupled with additional experimental information, we use
our results to extract information on the structure of three-prong tau decays
to charged kaons.Comment: 16 pages postscript file also available through
http://w4.lns.cornell.edu/public/CLN
A Search for Jet Handedness in Hadronic Decays
We have searched for signatures of polarization in hadronic jets from decays using the ``jet handedness'' method. The polar angle
asymmetry induced by the high SLC electron-beam polarization was used to
separate quark jets from antiquark jets, expected to be left- and
right-polarized, respectively. We find no evidence for jet handedness in our
global sample or in a sample of light quark jets and we set upper limits at the
95% C.L. of 0.063 and 0.099 respectively on the magnitude of the analyzing
power of the method proposed by Efremov {\it et al.}Comment: Revtex, 8 pages, 2 figure
Search for Baryon and Lepton Number Violating Decays of the Lepton
We have searched for five decay modes of the tau lepton that simultaneously
violate lepton and baryon number: tau -> anti-proton gamma, tau -> anti-proton
pi0, tau -> anti-proton eta, tau -> anti-proton 2pi0, and tau -> anti-proton
pi0eta. The data used in the search were collected with the CLEO II detector at
the Cornell Electron Storage Ring (CESR). The integrated luminosity of the data
sample is 4.7 fb^{-1}, corresponding to the production of 4.3 x 10^6 tau+tau-
events. No evidence is found for any of the decays, resulting in much improved
upper limits on the branching fractions for the two-body decays and first upper
limits for the three-body decays.Comment: 8 pages, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Observation of Radiative Leptonic Decay of the Tau Lepton
Using 4.68 fb^{-1} of e^+e^- annihilation data collected with the CLEO II
detector at the Cornell Electron Storage Ring (CESR) we have studied tau
radiative decays tau -> mu nu nu gamma and tau -> e nu nu gamma. For a 10 MeV
minimum photon energy in the tau rest frame, the branching fraction of
radiative tau decay to a muon or electron is measured to be
(3.61+-0.16+-0.35)*10^{-3} or (1.75+-0.06+-0.17)*10^{-2}, respectively. The
branching fractions are in agreement with the Standard Model theoretical
predictions.Comment: 11 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
A Measurement of the Decay Asymmetry Parameters in \Xi_{c}^{0}\to \X^{-}\pi^{+}
Using the CLEO II detector at the Cornell Electron Storage Ring we have
measured the decay asymmetry parameter in the decay . We find , using the world average value of
we obtain . The physically allowed range of a decay
asymmetry parameter is . Our result prefers a negative value:
is at the 90% CL. The central value occupies the
middle of the theoretically expected range but is not yet precise enough to
choose between models.Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
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