The acoustics of public square/places: a comparison between results from a computer simulation program and measurements in situ

http://www.odeon.dk/pdf/InterNoise2004.pd

Historias milenarias de presas y predadores: guanacos y humanos en Patagonia

Luego de la última extinción de grandes mamíferos –alrededor de 10.000 años atrás– se produjo un aumento demográfico del guanaco que posibilitó la rápida expansión de las poblaciones humanas. Este animal fue la principal presa de las poblaciones humanas cazadoras-recolectoras en Patagonia y proveyó alimento y materias primas (pieles, huesos, grasas, entre otros) durante milenios.Fundación Museo de La Plat

The HPS electromagnetic calorimeter

The Heavy Photon Search experiment (HPS) is searching for a new gauge boson, the so-called “heavy photon.” Through its kinetic mixing with the Standard Model photon, this particle could decay into an electron-positron pair. It would then be detectable as a narrow peak in the invariant mass spectrum of such pairs, or, depending on its lifetime, by a decay downstream of the production target. The HPS experiment is installed in Hall-B of Jefferson Lab. This article presents the design and performance of one of the two detectors of the experiment, the electromagnetic calorimeter, during the runs performed in 2015–2016. The calorimeter's main purpose is to provide a fast trigger and reduce the copious background from electromagnetic processes through matching with a tracking detector. The detector is a homogeneous calorimeter, made of 442 lead-tungstate (PbWO4) scintillating crystals, each read out by an avalanche photodiode coupled to a custom trans-impedance amplifier

Spatial structure and temporal dynamics of the human occupation of Neuquén (Argentinian Patagonia) during the late Pleistocene – Holocene

Se generó una base de datos conformada por 184 fechados georreferenciados procedentes de sitios arqueológicos de la provincia del Neuquén. Doce de ellos –realizados a partir de restos óseos humanos y faunísticos– son originales y algunos de ellos corresponden a áreas geográficas para las que aún no se contaba con datos. Se efectuaron análisis cuantitativos temporo-espaciales. Los resultados obtenidos sobre la base de datos cronológicos y geográficos permiten caracterizar el proceso de ocupación humana de Neuquén como temprano, mayormente continuo a lo largo del tiempo y espacialmente discontinuo. La profundidad temporal del poblamiento alcanza ca. 12.000 años calibrados AP y la ocupación del espacio se incrementó significativamente hacia el Holoceno tardío. La distribución de los sitios es discontinua y muestra concentraciones en áreas particulares cercanas a los cursos de agua permanente, mayoritariamente pericordilleranas, en tanto que en los espacios intermedios –las amplias planicies del este– no se registró una señal arqueológica marcada.A database was generated consisting of 184 georeferenced dates from archaeological sites in Neuquén Province. Twelve of these dates −taken from human and faunal bone remains− are original, and some correspond to geographical areas for which data were not previously available. Quantitative spatial-temporal analyzes were carried out. The results obtained on the basis of chronological and geographical data allow Neuquén’s human occupation process to be characterized as early, mostly continuous over time, and spatially discontinuous. The temporal depth of the settlement reaches ca. 12,000 years BP calibrated, with spacial occupation increasing significantly towards the late Holocene. The spatial distribution of the sites is discontinuous and shows concentrations in particular areas near the permanent water courses, mostly near the Andes, while in the intermediate spaces −the wide plains of the east− a marked archaeological signal was not recorded.Facultad de Ciencias Naturales y Muse

The Heavy Photon Search test detector

The Heavy Photon Search (HPS), an experiment to search for a hidden sector photon in fixed target electroproduction, is preparing for installation at the Thomas Jefferson National Accelerator Facility (JLab) in the Fall of 2014. As the first stage of this project, the HPS Test Run apparatus was constructed and operated in 2012 to demonstrate the experiment׳s technical feasibility and to confirm that the trigger rates and occupancies are as expected. This paper describes the HPS Test Run apparatus and readout electronics and its performance. In this setting, a heavy photon can be identified as a narrow peak in the e+e− invariant mass spectrum above the trident background or as a narrow invariant mass peak with a decay vertex displaced from the production target, so charged particle tracking and vertexing are needed for its detection. In the HPS Test Run, charged particles are measured with a compact forward silicon microstrip tracker inside a dipole magnet. Electromagnetic showers are detected in a PbW04 crystal calorimeter situated behind the magnet, and are used to trigger the experiment and identify electrons and positrons. Both detectors are placed close to the beam line and split top-bottom. This arrangement provides sensitivity to low-mass heavy photons, allows clear passage of the unscattered beam, and avoids the spray of degraded electrons coming from the target. The discrimination between prompt and displaced e+e− pairs requires the first layer of silicon sensors be placed only 10 cm downstream of the target. The expected signal is small, and the trident background huge, so the experiment requires very large statistics. Accordingly, the HPS Test Run utilizes high-rate readout and data acquisition electronics and a fast trigger to exploit the essentially 100% duty cycle of the CEBAF accelerator at JLab

PMm2: large photomultipliers and innovative electronics for the next-generation neutrino experiments

The next generation of proton decay and neutrino experiments, the post-SuperKamiokande detectors as those that will take place in megaton size water tanks, will require very large surfaces of photodetection and a large volume of data. Even with large hemispherical photomultiplier tubes, the expected number of channels should reach hundreds of thousands. A funded R&D program to implement a solution is presented here. The very large surface of photodetection is segmented in macro pixels made of 16 hemispherical (12 inches) photomultiplier tubes connected to an autonomous front-end which works on a triggerless data acquisition mode. The expected data transmission rate is 5 Mb/s per cable, which can be achieved with existing techniques. This architecture allows to reduce considerably the cost and facilitate the industrialization. This document presents the simulations and measurements which define the requirements for the photomultipliers and the electronics. A proto-type of front-end electronics was successfully tested with 16 photomultiplier tubes supplied by a single high voltage, validating the built-in gain adjustment and the calibration principle. The first tests and calculations on the photomultiplier glass led to the study of a new package optimized for a 10 bar pressure in order to sustain the high underwater pressure.Comment: 1 pdf file, 4 pages, 4 figures, NDIP08, submitted to Nucl. Instr. and Meth. Phys. Res.

The ALICE experiment at the CERN LHC

ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 161626 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008

sj-xlsx-2-hol-10.1177_09596836241231437 – Supplemental material for Central Argentina vegetation characteristics linked to extinct megafauna and some implications on human populations

Supplemental material, sj-xlsx-2-hol-10.1177_09596836241231437 for Central Argentina vegetation characteristics linked to extinct megafauna and some implications on human populations by Diego D Rindel, Bruno F Moscardi, Virginia A Cobos and Florencia Gordón in The Holocene</p