448 research outputs found
The impact of reduction in the benzene limit value in gasoline on airborne benzene, toluene and xylenes levels
Background benzene, toluene, xylenes (BTX) average concentrations have been measured over the urban agglomeration of Toulouse, France, during both springtime and summer periods of 1999 and 2001. The benzene average amount over the two Toulouse campaigns in 1999 is equal to 2.2 Ag/m³, very close to the French air quality standard and well under the average value of 5 Ag/m³ recommended by European Economic Community countries, recognising that those regulations are given for a whole year. BTX pollution over Toulouse has, in particular, been produced by motor vehicle exhaust gases. For the study conducted during the same periods of 2001, benzene concentrations were within the French quality value in the whole area. This is because the benzene limit value contained in gasoline went from 5% to 1%
since 2000 January 1. It will be important to measure benzene over annual periods in order to know its exact values over such a period and to observe its potential seasonal variations
Análisis de los valores obtenidos en el test del “clear” de bádminton para ergodinamómetro en función del sexo
Intoducción: Hemos diseñado y patentado un ergodinamómetro para medir la fuerza útil del gesto técnico, analizando un “clear” de bádminton, para ello hemos analizado a 10 jugadores de bádminton de nivel nacional (5 varones y 5 mujeres). Material y métodos: Hemos analizado tanto cualitativa como cuantitativamente la curvas de fuerza-tiempo y velocidad del disco-tiempo, comparando los resultados obtenidos en función del sexo. Resultados: Los varones tienen valores de fuerza máxima significativamente mayores que las mujeres, tiempos de aceleración significativamente menores, ángulos de aceleración significativamente mayores, fuerza explosiva significativamente mayor, valores de velocidad máxima del disco significativamente superiores a las mujeres, un punto de máxima velocidad significativamente inferior a las mujeres. Conclusiones: Existen diferencias significativas en la fuerza útil del “clear” de bádminton en función del sexo
Anàlisi dels valors obtinguts en el test del “clear” de bàdminton per a ergodinamòmetre en funció del sexe
Introducció: Hem dissenyat i patentat un ergodinamòmetre per mesurar la força útil del gest tècnic, analitzant un “clear” de bàdminton; per fer-ho, hem analitzat 10 jugadors de bàdminton de nivell nacional (5 barons i 5 dones). Material i mètodes: Hem analitzat tant qualitativament com quantitativament les corbes de força-temps i velocitat del disc-Temps, i hem comparat els resultats obtinguts en funció del sexe. Resultats: Els barons tenen valors de força màxima significativament més grans que no pas les dones, temps d’acceleració significativament menors, angles d’acceleració significativament majors, força explosiva significativament major, valors de velocitat màxima del disc significativament superiors a les dones., un punt de màxima velocitat significativament inferior a les dones. Conclusions: Hi ha diferències significatives en la força útil del “clear” de bàdminton en funció del sexe
Programa de calificación de actividades productivas y servicios de carácter industrial
111 p.El año 2001, el Servicio de Salud del Maule realizó un convenio con la Universidad de Talca con la finalidad de que alumnos de la carrera de Ingeniería de Ejecución Mecánica prestaran asesoría técnica en temas Medioambientales, Seguridad y Salud Ocupacional, así como también de la aplicación general en diseño y ejecución de proyectos relacionados con el rubro industrial, para que el pequeño y mediano empresario pudieran responder frente a una serie de requisitos solicitados en un programa que el Servicio de Salud del Maule comenzaba a implementar, y que por supuesto tenían plena relación con los temas mencionados anteriormente, para que de este modo el Servicio de Salud emitiera la correspondiente calificación de la actividad económica en estudio. Este programa despierta un gran interés ya que somete a estudio a todas aquellas actividades productivas y de carácter industrial que generalmente producen un impacto negativo sobre el ambiente, tema de gran importancia ya que actualmente se manifiesta un aumento a la tendencia de proteger el entorno natural. Este programa de asesoría desarrollado con variadas actividades económicas permite apreciar una serie de debilidades que presenta el procedimiento, entre las cuales se pueden mencionar las siguientes: La principal debilidad del programa radica en que este fue planteado para la realidad industrial de la Región Metropolitana y no se adapta adecuadamente para una realidad distinta como lo serian las actividades industriales de la VII Región.
Una segunda debilidad radica en los diferentes criterios existentes a la hora de aplicar el programa por las distintas oficinas de Salud Ambiental de la Región, lo que no permite una correcta y común adaptación del programa. Poco respaldo por parte de los fiscalizadores del Servicio de Salud del Maule correspondientes a cada oficina, por considerar el programa de calificación como un procedimiento engorroso y de co Poca adaptabilidad del procedimiento para microempresarios, por contener requisitos que conllevan un de elevado costo para estos. La falta de fiscalización eficaz por falta de recursos económicos, equipos humanos debidamente calificados, recursos técnicos y tecnológicos. Con el fin de hacer frente a esta problemática, los autores de este trabajo plantean un objetivo general como también una serie de tareas y objetivos específicos para lograr su respectivo cumplimiento.mplicada aplicación
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at TeV
The elliptic, , triangular, , and quadrangular, , azimuthal
anisotropic flow coefficients are measured for unidentified charged particles,
pions and (anti-)protons in Pb-Pb collisions at TeV
with the ALICE detector at the Large Hadron Collider. Results obtained with the
event plane and four-particle cumulant methods are reported for the
pseudo-rapidity range at different collision centralities and as a
function of transverse momentum, , out to GeV/.
The observed non-zero elliptic and triangular flow depends only weakly on
transverse momentum for GeV/. The small dependence
of the difference between elliptic flow results obtained from the event plane
and four-particle cumulant methods suggests a common origin of flow
fluctuations up to GeV/. The magnitude of the (anti-)proton
elliptic and triangular flow is larger than that of pions out to at least
GeV/ indicating that the particle type dependence persists out
to high .Comment: 16 pages, 5 captioned figures, authors from page 11, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186
Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at TeV
The inclusive transverse momentum () distributions of primary
charged particles are measured in the pseudo-rapidity range as a
function of event centrality in Pb-Pb collisions at
TeV with ALICE at the LHC. The data are presented in the range
GeV/ for nine centrality intervals from 70-80% to 0-5%.
The Pb-Pb spectra are presented in terms of the nuclear modification factor
using a pp reference spectrum measured at the same collision
energy. We observe that the suppression of high- particles strongly
depends on event centrality. In central collisions (0-5%) the yield is most
suppressed with at -7 GeV/. Above
GeV/, there is a significant rise in the nuclear modification
factor, which reaches for GeV/. In
peripheral collisions (70-80%), the suppression is weaker with almost independently of . The measured nuclear
modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/284
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
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