423 research outputs found
The Kolmogorov-Smirnov test and its use for the identification of fireball fragmentation
We propose an application of the Kolmogorov-Smirnov test for rapidity
distributions of individual events in ultrarelativistic heavy ion collisions.
The test is particularly suitable to recognise non-statistical differences
between the events. Thus when applied to a narrow centrality class it could
indicate differences between events which would not be expected if all events
evolve according to the same scenario. In particular, as an example we assume
here a possible fragmentation of the fireball into smaller pieces at the
quark/hadron phase transition. Quantitative studies are performed with a Monte
Carlo model capable of simulating such a distribution of hadrons. We conclude
that the Kolmogorov-Smirnov test is a very powerful tool for the identification
of the fragmentation process.Comment: 9 pages, 10 figure
Orchestrating Tuple-based Languages
The World Wide Web can be thought of as a global computing architecture supporting the deployment of distributed networked applications. Currently, such applications can be programmed by resorting mainly to two distinct paradigms: one devised for orchestrating distributed services, and the other designed for coordinating distributed (possibly mobile) agents. In this paper, the issue of designing a pro-
gramming language aiming at reconciling orchestration and coordination is investigated. Taking as starting point the orchestration calculus Orc and the tuple-based coordination language Klaim, a new formalism is introduced combining concepts and primitives of the original calculi.
To demonstrate feasibility and effectiveness of the proposed approach, a prototype implementation of the new formalism is described and it is then used to tackle a case study dealing with a simplified but realistic electronic marketplace, where a number of on-line stores allow client
applications to access information about their goods and to place orders
Nutrition support in cancer patients: a brief review and suggestion for standard indications criteria
The indications of nutrition support in cancer patients have been subject to controversy. Most studies address the effects of the method in increasing the survival or the tumor response rate. Few studies have focused on the effects in improving quality of life. After a brief review, we described the results of a study, which evaluated the effects of protein-caloric supplementation on the quality of life parameters in a group of head and neck cancer patients submitted to radiotherapy. The results support the suggestion of creating standard criteria to indicate nutrition support in cancer patients. Based on our findings, nutrition support should be indicated for cancer patients considering the potential effects to improve the quality of life
Carrier - envelope phase-tagged imaging of the controlled electron acceleration from SiO2 nanospheres in intense few-cycle laser fields
Waveform-controlled light fields offer the possibility of manipulating
ultrafast electronic processes on sub-cycle timescales. The optical lightwave
control of the collective electron motion in nanostructured materials is key
to the design of electronic devices operating at up to petahertz frequencies.
We have studied the directional control of the electron emission from 95 nm
diameter SiO2 nanoparticles in few-cycle laser fields with a well-defined
waveform. Projections of the three-dimensional (3D) electron momentum
distributions were obtained via single-shot velocity-map imaging (VMI), where
phase tagging allowed retrieving the laser waveform for each laser shot. The
application of this technique allowed us to efficiently suppress background
contributions in the data and to obtain very accurate information on the
amplitude and phase of the waveform-dependent electron emission. The
experimental data that are obtained for 4 fs pulses centered at 720 nm at
different intensities in the range (1â4) Ă 1013 W cmâ2 are compared to quasi-
classical mean-field Monte-Carlo simulations. The model calculations identify
electron backscattering from the nanoparticle surface in highly dynamical
localized fields as the main process responsible for the energetic electron
emission from the nanoparticles. The local field sensitivity of the electron
emission observed in our studies can serve as a foundation for future research
on propagation effects for larger particles and field-induced material changes
at higher intensities
An all-solid-state laser source at 671 nm for cold atom experiments with lithium
We present an all solid-state narrow line-width laser source emitting
output power at delivered in a
diffraction-limited beam. The \linebreak source is based on a
fre-quency-doubled diode-end-linebreak pumped ring laser operating on the
transition in Nd:YVO. By using
periodically-poled po-tassium titanyl phosphate (ppKTP) in an external build-up
cavity, doubling efficiencies of up to 86% are obtained. Tunability of the
source over is accomplished. We demonstrate the suitability of
this robust frequency-stabilized light source for laser cooling of lithium
atoms. Finally a simplified design based on intra-cavity doubling is described
and first results are presented
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