137 research outputs found
Terrestrial Nutrient and Sediment Fluxes to the Coastal Waters of West Maui, Hawai'i
Water-quality degradation is often linked to land use practices in
adjacent and upstream areas. Such linkages are here explored for the Lahaina District
of Maui, Hawai'i, where severe algae blooms in 1989 and 1991 prompted public
concern and a subsequent search for the factors contributing to algal growth. Because
we expected that elevated nutrient levels might play a role in the blooms, this study
examined the nutrient and sediment budgets from terrestrial sources entering the
coastal waters. Although our work did not show any definitive causal relationship
between algal growth and terrestrial nutrient and sediment loading, it clearly established
that the principal agricultural activities in the area of sugarcane and pineapple
cultivation contribute elevated loads of nutrients and sediments to the coastal waters.
Likewise, disposal of treated domestic sewage effluent into subsurface injection
wells contributes substantial nutrient loads to the coastal waters. Conversely, golf
courses appear to have negligible impacts on the nutrient and sediment loading of
coastal waters in the area. Finally, although groundwater discharges substantially
greater annual nutrient loads than streamflow, the groundwater discharge is fairly
evenly distributed in time and is dispersed over nearly 25 km of shoreline. Streamflow,
however, often discharges intensely for short periods of time at a few discrete
locations, and thus may have substantial impact locally on coastal water quality
Search for Single Top Production at LEP
Single top production in e+e- annihilations is searched for in data collected
by the L3 detector at centre-of-mass energies from 189 to 209 GeV,
corresponding to a total integrated luminosity of 634 pb-1. Investigating
hadronic and semileptonic top decays, no evidence of single top production at
LEP is obtained and upper limits on the single top cross section as a function
of the centre-of-mass energy are derived. Limits on possible anomalous
couplings, as well as on the scale of contact interactions responsible for
single top production are determined
Flavour Independent Search for Neutral Higgs Bosons at LEP
A flavour independent search for the CP-even and CP-odd neutral Higgs bosons
h and A is performed in 624/pb of data collected with the L3 detector at LEP at
centre-of-mass energies between 189 and 209GeV. Higgs boson production through
the e^+e^- -> Z h and the e^+e^- ->h A processes is considered and decays of
the Higgs bosons into hadrons are studied. No significant signal is observed
and 95% confidence level limits on the hZZ and hAZ couplings are derived as a
function of the Higgs boson masses. Assuming the Standard Model cross section
for the Higgs-strahlung process and a 100% branching fraction into hadrons, a
95% confidence level lower limit on the mass of the Higgs boson is set at
110.3GeV
Measurement of the Probability of Gluon Splitting into Charmed Quarks in Hadronic Z Decays
We have measured the probability, n(g->cc~), of a gluon splitting into a
charm-quark pair using 1.7 million hadronic Z decays collected by the L3
detector. Two independent methods have been applied to events with a three-jet
topology. One method relies on tagging charmed hadrons by identifying a lepton
in the lowest energy jet. The other method uses a neural network based on
global event shape parameters. Combining both methods, we measure n(g->cc~)=
[2.45 +/- 0.29 +/- 0.53]%
Search for Neutral Higgs Bosons of the Minimal Supersymmetric Standard Model in e+e- Interactions at root(s)=192-202GeV
A search for the lightest neutral CP-even and the neutral CP-odd Higgs bosons
of the Minimal Supersymmetric Standard Model is performed using 233.2 pb-1 of
integrated luminosity collected with the L3 detector at LEP at centre-of-mass
energies 192-202 GeV. No signal is observed and lower mass limits are given as
a function of tan(beta) for two scalar top mixing hypotheses. For tan(beta)
greater than 0.8, they are mh > 83.4 GeV and mA > 83.8 GeV at 95 % confidence
level
3D effects of edge magnetic field configuration on divertor/scrape-off layer transport and optimization possibilities for a future reactor
This paper assesses the three-dimensional (3D) effects of the edge magnetic field structure on divertor/scrape-off layer transport, based on an inter-machine comparison of experimental data and on the recent progress of 3D edge transport simulation. The 3D effects are elucidated as a consequence of competition between transports parallel ( ) and perpendicular ( ) to the magnetic field, in open field lines cut by divertor plates, or in magnetic islands. The competition has strong impacts on divertor functions, such as determination of the divertor density regime, impurity screening and detachment control. The effects of magnetic perturbation on the edge electric field and turbulent transport are also discussed. Parameterization to measure the 3D effects on the edge transport is attempted for the individual divertor functions. Based on the suggested key parameters, an operation domain of the 3D divertor configuration is discussed for future devices
Studies of Hadronic Event Structure in e+e- Annihilation from 30 GeV to 209 GeV with the L3 Detector
In this Report, QCD results obtained from a study of hadronic event structure
in high energy e^+e^- interactions with the L3 detector are presented. The
operation of the LEP collider at many different collision energies from 91 GeV
to 209 GeV offers a unique opportunity to test QCD by measuring the energy
dependence of different observables. The main results concern the measurement
of the strong coupling constant, \alpha_s, from hadronic event shapes and the
study of effects of soft gluon coherence through charged particle multiplicity
and momentum distributions.Comment: To appear in Physics Report
Uso da técnica de swim-up para a remoção do Vírus da Artrite Encefalite Caprina do sêmen de reprodutores infectados
Genetic improvement trends in agronomic performances and end-use quality characteristics among hard red winter wheat cultivars in Nebraska
Production of Single W Bosons at LEP and Measurement of WWgamma Gauge Coupling Parameters
Single W boson production in electron-positron collisions is studied with the
L3 detector at centre-of-mass energies between 192 GeV and 209 GeV. Events with
two acoplanar hadronic jets or a single energetic lepton are selected, and the
single W cross section is measured. Combining the results with measurements at
lower centre-of-mass energies, the ratio of the measured cross section to the
Standard Model expectation is found to be 1.12^{+0.11}_{-0.10}+/-0.03. From all
single W data, the WWgamma gauge coupling parameter kappa_gamma is measured to
be 1.116^{+0.082}_{-0.086}+/-0.068
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