1,810 research outputs found
The ALICE electromagnetic calorimeter high level triggers
The ALICE (A Large Ion Collider Experiment) detector yields a huge sample of
data from different sub-detectors. On-line data processing is applied to select
and reduce the volume of the stored data. ALICE applies a multi-level hardware
trigger scheme where fast detectors are used to feed a three-level (L0, L1, and
L2) deep chain. The High-Level Trigger (HLT) is a fourth filtering stage
sitting logically between the L2 trigger and the data acquisition event
building. The EMCal detector comprises a large area electromagnetic calorimeter
that extends the momentum measurement of photons and neutral mesons up to
GeV/c, which improves the ALICE capability to perform jet
reconstruction with measurement of the neutral energy component of jets. An
online reconstruction and trigger chain has been developed within the HLT
framework to sharpen the EMCal hardware triggers, by combining the central
barrel tracking information with the shower reconstruction (clusters) in the
calorimeter. In the present report the status and the functionality of the
software components developed for the EMCal HLT online reconstruction and
trigger chain will be discussed, as well as preliminary results from their
commissioning performed during the 2011 LHC running period.Comment: Proceeding for the CHEP 2012 Conferenc
The Stellar Content of Obscured Galactic Giant HII Regions. VI: W51A
We present K-band spectra of newly born OB stars in the obscured Galactic
giant H II region W51A and ~ 0.8'' angular resolution images in the J, H and
K_S-bands. Four objects have been spectroscopically classified as O-type stars.
The mean spectroscopic parallax of the four stars gives a distance of 2.0 \pm
0.3 kpc (error in the mean), significantly smaller than the radio recombination
line kinematic value of 5.5 kpc or the values derived from maser propermotion
observations (6--8 kpc). The number of Lyman continuum photons from the
contribution of all massive stars (NLyc ~ 1.5 x 10^{50} s^{-1}) is in good
agreement with that inferred from radio recombination lines (NLyc = 1.3 x
10^{50} s^{-1}) after accounting for the smaller distance derived here.
We present analysis of archival high angular resolution images (NAOS CONICA
at VLT and T-ReCS at Gemini) of the compact region W51 IRS2. The K_S--band
images resolve the infrared source IRS~2 indicating that it is a very young
compact HII region. Sources IRS2E was resolved into compact cluster (within 660
AU of projected distance) of 3 objects, but one of them is just bright extended
emission. W51d1 and W51d2 were identified with compact clusters of 3 objects
(maybe 4 in the case of W51d1) each one. Although IRS~2E is the brightest
source in the K-band and at 12.6 \micron, it is not clearly associated with a
radio continuum source. Our spectrum of IRS~2E shows, similar to previous work,
strong emission in Br and HeI, as well as three forbidden emission
lines of FeIII and emission lines of molecular hydrogen (H_2) marking it as a
massive young stellar object.Comment: 31 pages and 9 figures, submitted to A
Do slower life history strategies reduce sociodemographic sex differences?
This study examines the relations between sociodemographic sex differences and life history strategies in the populations of Mexican States. Sex differences in anatomy and behavior was measured with traits such as educational achievement, mortality, and morbidity. The data were obtained from the Instituto Nacional de Estadística y Geografía (INEGI) and sampled from thirty-one Mexican states and the Federal District (N = 32). An extension analysis was performed selecting only the sex ratio variables that had a correlation with the slow Life History factor greater than or equal to an absolute value of .25. A unit-weighted sex ratio factor was created using these variables. Across 32 Mexican states, the correlation between latent slow life history and sex ratio was .57 (p .05). These results are consistent with our hypothesis that slower life histories favor reduced sexual dimorphism in physiology and behavior among human subnational populations. The results of the study further understanding of variations in population sex differences, male-biased behaviors toward sexual equality, and the differences among subnational (regional) populations within the United States of Mexico.
DOI:10.2458/azu_jmmss_v6i1_chavarria_miner
Composition chimique de l’huile essentielle des fleurs de Lanneavelutina (Anacardiaceae) du Mali
La présente étude a pour but la détermination de la composition chimique de l’huile essentielle des fleurs de Lanneavelutina, une plante mellifère répertoriée au Mali (Cissé 2004). Cette huile essentielle a été obtenue par entrainement à la vapeur d’eau avec des rendements de l’ordre de 0.04%. Le composé majoritaire identifié est le beta-caryophyllène (22-36%). Elle contient essentiellement des sesquiterpènes, des hydrocarbures saturés et des hydrocarbures oxygénés non terpéniques.Mots clés: Composition chimique, mellifère, entrainement à la vapeur d’eau, sesquiterpène
Parabolic trough solar collectors : design for increasing efficiency
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 193-200).Parabolic trough collectors are a low cost implementation of concentrated solar power technology that focuses incident sunlight onto a tube filled with a heat transfer fluid. The efficiency and cost of the parabolic trough collector designs is influenced by structural stiffness, choice of materials, assembly tolerances, mirror cleanliness and wear. Current performance estimates of solar trough optical field efficiencies are 54.2% [1]. The goal of this research is to identify general methods and specific design concepts for achieving increased collector efficiency. This thesis has investigated improvements in the design of a parabolic trough module by looking first at the overall structural concept of the collector to reduce complexity while maintaining structural stability under wind loading conditions. In the process of evaluating the feasibility of one such concept, a monolithic reflector panel with a mirror film front surface, details related to the mirror surface efficiency were investigated. At the panel-structure to mirror interface, surface roughness of the underlying structural backing was studied to understand performance effects on the mirror film surface that would make one backing material potentially more suitable than another would. In this case it was found that three materials tested: gel-coated fiberglass, rolled aluminum, and rolled steel were all similarly effective when compared to a more expensive mirrored aluminum backing material. When looking at the integration of the larger structural changes with the factors that affect surface reflectivity of parabolic mirrors, it became apparent that contamination of the surfaces and cleaning were major factors in reduced module effectiveness. Given that the conceptual development of the structure is ongoing, research into contamination factors and potential cleaning solutions were considered in such a way that panel cleaning solutions could be integrated into the trough module design from the start. A vortex generator cleaning concept, which uses V-shaped extruded forms to create vortices over a mirror panel in the presence of flow over the surface, was tested as a passive cleaning solution.by Stacy L. Figueredo.Ph.D
Reducción del consumo eléctrico debido a climatización en un salón de un edificio educativo del NEA
La sociedad actual demanda condiciones de confort que permitan desarrollar actividades con elevada productividad, en el NEA alcanzar las condiciones apropiadas de temperatura y humedad en edificios antiguos implica un excesivo consumo de energía eléctrica. Se presenta la simulación computacional mediante el software Energy Plus del comportamiento térmico de un aula del edificio de la Facultad Regional Resistencia de la Universidad Tecnológica Nacional. Se validan los resultados de la simulación con datos experimentales de temperatura interior para idénticas condiciones exteriores de radiación solar y temperatura. Se obtiene la carga térmica instantánea y la disminución potencial de consumo de energía eléctrica destinada a la climatización para diferentes casos de rehabilitación térmica del salón. Se verifica la exactitud del modelo confrontando los resultados de la simulación con los datos internos medidos en el aula. Se demuestra también la capacidad del software como herramienta para mejorar la eficiencia energética de edificios y garantizar las condiciones de confort.Today’s society demands high comfort conditions to carry out activities with high productivity, in the Argentine Northeast achieving the appropriate conditions of temperature and humidity in old buildings involves excessive power consumption. It is presented the computer simulation by the Energy Plus software about thermal behavior of a classroom in the building of the Facultad Regional Resistencia of the Universidad Tecnológica Nacional. The simulation results are validated with measured data of indoor temperature for the same exterior conditions of solar radiation and temperature. Is obtained the instantaneous thermal charge and the decrease of potential consumption of electricity for air conditioning in different cases of thermal rehabilitation. The accuracy of the model is verified by comparing the simulation results with internal data measured in the classroom. The ability of the software as a tool to improve the energy efficiency of buildings and ensure comfort conditions is also demonstrated.Tema 8: Energías renovables, modelización y simulación.Facultad de Arquitectura y Urbanism
Reducción del consumo eléctrico debido a climatización en un salón de un edificio educativo del NEA
La sociedad actual demanda condiciones de confort que permitan desarrollar actividades con elevada productividad, en el NEA alcanzar las condiciones apropiadas de temperatura y humedad en edificios antiguos implica un excesivo consumo de energía eléctrica. Se presenta la simulación computacional mediante el software Energy Plus del comportamiento térmico de un aula del edificio de la Facultad Regional Resistencia de la Universidad Tecnológica Nacional. Se validan los resultados de la simulación con datos experimentales de temperatura interior para idénticas condiciones exteriores de radiación solar y temperatura. Se obtiene la carga térmica instantánea y la disminución potencial de consumo de energía eléctrica destinada a la climatización para diferentes casos de rehabilitación térmica del salón. Se verifica la exactitud del modelo confrontando los resultados de la simulación con los datos internos medidos en el aula. Se demuestra también la capacidad del software como herramienta para mejorar la eficiencia energética de edificios y garantizar las condiciones de confort.Today’s society demands high comfort conditions to carry out activities with high productivity, in the Argentine Northeast achieving the appropriate conditions of temperature and humidity in old buildings involves excessive power consumption. It is presented the computer simulation by the Energy Plus software about thermal behavior of a classroom in the building of the Facultad Regional Resistencia of the Universidad Tecnológica Nacional. The simulation results are validated with measured data of indoor temperature for the same exterior conditions of solar radiation and temperature. Is obtained the instantaneous thermal charge and the decrease of potential consumption of electricity for air conditioning in different cases of thermal rehabilitation. The accuracy of the model is verified by comparing the simulation results with internal data measured in the classroom. The ability of the software as a tool to improve the energy efficiency of buildings and ensure comfort conditions is also demonstrated.Tema 8: Energías renovables, modelización y simulación.Facultad de Arquitectura y Urbanism
- …