14,149 research outputs found
Measurement of light mesons at RHIC by the PHENIX experiment
The PHENIX experiment at RHIC has measured a variety of light neutral mesons
(, K, , , , ) via
multi-particle decay channels over a wide range of transverse momentum. A
review of the recent results on the production rates of light mesons in p+p and
their nuclear modification factors in d+Au, Cu+Cu and Au+Au collisions at
different energies is presented.Comment: 5 pages, 4 figures, talk given at Hard Probes 2008 conference in La
Toja, Spain. submitted to EPJ
Nondispersive X-ray emission analysis for geochemical exploration
Nondispersive X-ray emission technique uses lightweight, and rugged X-ray fluorescence units. The X-ray pulse-height spectra is excited by radioactive isotope sources. The technique is applicable for quantitative and qualitative analyses on complex chemical systems, and satisfies the goals for a lunar geochemical exploration device
Converting rain into drinking water: Quality issues and technological advances
With growing pressures on water supplies worldwide, rainwater harvesting is increasingly seen as a viable option to provide drinking water to an ever expanding population, particularly in developing countries. However, rooftop runoff is not without quality issues. Microbiological and chemical contamination have been detected in several studies, well above local and international guidelines, posing a health risk for consumers. Our research explores the use of silver ions, combined with conventional filtration and settling mechanisms, as a safe and affordable model for purification that can be applied on a small scale. The complete systems were installed and tested in rural communities in a Mexican semi-arid region. Efficiencies up to 99.9% were achieved in the removal of indicator microorganisms, with a marked exception where cross-contamination from external seepage occurs. Sites without overhanging branches or with relatively clean surfaces show an absence of total coliforms in the untreated runoff, compared with others where values as high as 1,650 CFU/100 ml were recorded. Thus, given adequate maintenance, the system can successfully deliver high quality drinking water, even when storage is required for long periods of time. © IWA Publishing 2011
Remote sensing X-ray spectrometer
Spectrometer measures chemical composition of lunar rocks by remote sensing from orbit and senses lunar X-rays produced by interaction of solar X-rays and elements on the lunar surface. Instrument features high sensitivity, data handling system that accumulates and prepares data for telemetry, and automatic calibration
Classification of integrable equations on quad-graphs. The consistency approach
A classification of discrete integrable systems on quad-graphs, i.e. on
surface cell decompositions with quadrilateral faces, is given. The notion of
integrability laid in the basis of the classification is the three-dimensional
consistency. This property yields, among other features, the existence of the
discrete zero curvature with a spectral parameter. For all integrable systems
of the obtained exhaustive list, the so called three-leg forms are found. This
establishes Lagrangian and symplectic structures for these systems, and the
connection to discrete systems of the Toda type on arbitrary graphs.
Generalizations of these ideas to the three-dimensional integrable systems and
to the quantum context are also discussed
Classification of integrable discrete equations of octahedron type
We use the consistency approach to classify discrete integrable 3D equations
of the octahedron type. They are naturally treated on the root lattice
and are consistent on the multidimensional lattice . Our list includes
the most prominent representatives of this class, the discrete KP equation and
its Schwarzian (multi-ratio) version, as well as three further equations. The
combinatorics and geometry of the octahedron type equations are explained. In
particular, the consistency on the 4-dimensional Delaunay cells has its origin
in the classical Desargues theorem of projective geometry. The main technical
tool used for the classification is the so called tripodal form of the
octahedron type equations.Comment: 53 pp., pdfLaTe
High transverse momentum suppression and surface effects in Cu+Cu and Au+Au collisions within the PQM model
We study parton suppression effects in heavy-ion collisions within the Parton
Quenching Model (PQM). After a brief summary of the main features of the model,
we present comparisons of calculations for the nuclear modification and the
away-side suppression factor to data in Au+Au and Cu+Cu collisions at 200 GeV.
We discuss properties of light hadron probes and their sensitivity to the
medium density within the PQM Monte Carlo framework.Comment: Comments: 6 pages, 8 figures. To appear in the proceedings of Hot
Quarks 2006: Workshop for Young Scientists on the Physics of
Ultrarelativistic Nucleus-Nucleus Collisions, Villasimius, Italy, 15-20 May
200
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