512 research outputs found
Characterization of Spark Ignition energy transfer by optical and non-optical diagnostics
International audienceThis study focuses on the measurement of energy deposited in the fluid by an electrical discharge in different test conditions. An experimental setup is developed for this purpose: a transistorized coil system supplies the electrical energy input for the spark, from 25 to 45 mJ, which is measured at a pair of pin-to-pin electrodes. The energy deposit, ranging from 8 to 15 mJ, is measured using two different techniques: constant volume calorimetry, and Speckle-based Background-Oriented Schlieren (SBOS). Efficiency of the energy transfer is estimated. Calorimetry shows that efficiency depends on inter-electrode gap and gas conditions, increasing with pressure and gap. SBOS provides spatial distributions of density field, temperature and enthalpy. Calorimetry and SBOS provide similar results in terms of the rate of energy deposit over time. Different test conditions are obtained changing inter-electrode gap (from 1 to 3 mm), energy input and gas pressure (from 0.5 to 4 bar)
Big data, small concepts:Histosophy as an approach to longue-durée history
In this essay, we sketch out a method, histosophy, which makes possible the study of intellectual history and conceptual genealogy both in depth and over long periods of time. Histosophy uses digital tools to survey âlarge issues within small compasses.â A genealogy of signifiers, it considers metonymic parts of a problem in order to contribute precisely and coherently to a larger perspective. We outline the theoretical contours of our approach. We exemplify how it works in practice by looking at the signifier âesprit de corpsâ, the study of which is presented in detail in the histosophical book The Genealogy of Esprit de Corps(Edinburgh University Press, 2019). The phrase âesprit de corpsâ has been widely used since the eighteenth century in different discourses (political, military, sociological, etc.), but it is sufficiently limited that its genealogy can be traced across centuries and nations with precision, coherence, clarity, and with the help of automated search engines. By contrast, related but bigger concepts like freedom, individualism or solidarity are part of dozens of disparate and fuzzy discourses, so often uttered that the analysis of modern uses is problematic. The histosophical methodology is applicable in six discrete stages, here outlined
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
Soil macrofauna communities in Brazilian land-use systems
Soil animal communities include more than 40 higher-order taxa, representing over 23% of all described species. These animals have a wide range of feeding sources and contribute to several important soil functions and ecosystem services. Although many studies have assessed macroinvertebrate communities in Brazil, few of them have been published in journals and even fewer have made the data openly available for consultation and further use. As part of ongoing efforts to synthesise the global soil macrofauna communities and to increase the amount of openly-accessible data in GBIF and other repositories related to soil biodiversity, the present paper provides links to 29 soil macroinvertebrate datasets covering 42 soil fauna taxa, collected in various land-use systems in Brazil. A total of 83,085 georeferenced occurrences of these taxa are presented, based on quantitative estimates performed using a standardised sampling method commonly adopted worldwide to collect soil macrofauna populations, i.e. the TSBF (Tropical Soil Biology and Fertility Programme) protocol. This consists of digging soil monoliths of 25 x 25 cm area, with handsorting of the macroinvertebrates visible to the naked eye from the surface litter and from within the soil, typically in the upper 0-20 cm layer (but sometimes shallower, i.e. top 0-10 cm or deeper to 0-40 cm, depending on the site). The land-use systems included anthropogenic sites managed with agricultural systems (e.g. pastures, annual and perennial crops, agroforestry), as well as planted forests and native vegetation located mostly in the southern Brazilian State of ParanĂĄ (96 sites), with a few additional sites in the neighbouring states of SĂŁo Paulo (21 sites) and Santa Catarina (five sites). Important metadata on soil properties, particularly soil chemical parameters (mainly pH, C, P, Ca, K, Mg, Al contents, exchangeable acidity, Cation Exchange Capacity, Base Saturation and, infrequently, total N), particle size distribution (mainly % sand, silt and clay) and, infrequently, soil moisture and bulk density, as well as on human management practices (land use and vegetation cover) are provided. These data will be particularly useful for those interested in estimating land-use change impacts on soil biodiversity and its implications for below-ground foodwebs, ecosystem functioning and ecosystem service delivery.Quantitative estimates are provided for 42 soil animal taxa, for two biodiversity hotspots: the Brazilian Atlantic Forest and Cerrado biomes. Data are provided at the individual monolith level, representing sampling events ranging from February 2001 up to September 2016 in 122 sampling sites and over 1800 samples, for a total of 83,085 ocurrences
Species interactions increase the temporal stability of community productivity in Pinus sylvestris-Fagus sylvatica
Wi-Fi service enhancement at CERN
Since the early 2000âs, the number of mobile devices connected to CERNâs internal network has increased from just a handful to well over 10,000. Wireless access is no longer simply ânice to haveâ or just for conference and meeting rooms; support for mobility is expected by most, if not all, of the CERN community. In this context, a full renewal of the CERN Wi-Fi network has been launched to deliver a state-of-the-art campus-wide Wi-Fi Infrastructure. We aim to deliver, in more than 200 office buildings with a surface area of over 400,000m2 and including many high-priority and high-occupation zones, an end-user experience comparable, for most applications, to a wired connection and with seamless mobility support. We describe here the studies and tests performed at CERN to ensure the solution we are deploying can meet these goals as well as delivering a single, simple, flexible and open management platform
[Carta de Louis Doynel a Benito PĂ©rez GaldĂłs (13 de marzo de 1901, Francia)]
Copia digital. España : Ministerio de Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 202
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