1,464 research outputs found
Režim proudění v axiálním hydrostatickém ložisku s centrální drážkou
This paper deals with the fluid flow in the axial hydrostatic bearing with the central groove. The type of flow in the narrow gap is defined by the dimensionless Reynolds number. The influence of the groove shape on the pressure field in axial hydrostatic bearing is investigated. Numerical modelling and evaluation of the flow field parameters is done using Ansys Fluent software.Režim proudění v axiálním hydrostatickém ložisku s centrální drážko
EFFECT OF DIFFERENT CYCLING CONDITIONS ON SAGITALL AND FRONTAL LOWER LIMB KINEMATICS OF COMPETITIVE AND RECREATIONAL CYCLISTS
The aim of the current study was to compare sagittal and frontal hip, knee and ankle joint kinematics between competitive and recreational road cyclists across different workloads and pedalling cadences. Five competitive and five recreational healthy male road cyclists performed four conditions (85 rpm and 95 rpm at 200 W and 65 rpm and 75 rpm at 230 W) in random order to cover a variety cadences and workloads used during competition or training (plane, slight hill, medium hill and steep hill). Lower limb kinematic data were collected with nine infrared cameras. T-test and effect size statistics established significant differences in the power phase (0-180") of the crank cycle for knee abduction, knee extension and hip adduction between the two groups. Increase in hip and knee frontal plane motion indicated altered pedalling technique for recreational cyclists
Measurement of jet suppression in central Pb-Pb collisions at root s(NN)=2.76 TeV
The transverse momentum(p(T)) spectrum and nuclear modification factor (R-AA) of reconstructed jets in 0-10% and 10-30% central Pb-Pb collisions at root s(NN) = 2.76 TeV were measured. Jets were reconstructed using the anti-k(T) jet algorithm with a resolution parameter of R = 0.2 from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal). The jet p(T) spectra are reported in the pseudorapidity interval of \eta(jet)\ LT 0.5 for 40 LT p(T), jet LT 120 GeV/c in 0-10% and for 30 LT p(T), jet LT 100 GeV/c in 10-30% collisions. Reconstructed jets were required to contain a leading charged particle with p(T) GT 5 GeV/c to suppress jets constructed from the combinatorial background in Pb-Pb collisions. The leading charged particle requirement applied to jet spectra both in pp and Pb-Pb collisions had a negligible effect on the R-AA. The nuclear modification factor R-AA was found to be 0.28 +/- 0.04 in 0-10% and 0.35 +/- 0.04 in 10-30% collisions, independent of p(T), jet within the uncertainties of the measurement. The observed suppression is in fair agreement with expectations from two model calculations with different approaches to jet quenching. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V
Measurement of charged jet production cross sections and nuclear modification in p-Pb collisions at root s(NN)=5.02 TeV
Charged jet production cross sections in p-Pb collisions at root s(NN) = 5.02 TeV measured with the ALICE detector at the LHC are presented. Using the anti-k(T) algorithm, jets have been reconstructed in the central rapidity region from charged particles with resolution parameters R = 0.2 and R = 0.4. The reconstructed jets have been corrected for detector effects and the underlying event background. To calculate the nuclear modification factor, R-pPb, of charged jets in p-Pb collisions, a pp reference was constructed by scaling previously measured charged jet spectra at root s = 7 TeV. In the transverse momentum range 20 LT = p(T, chjet) LT = 120 GeV/c, R-pPb is found to be consistent with unity, indicating the absence of strong nuclear matter effects on jet production. Major modifications to the radial jet structure are probed via the ratio of jet production cross sections reconstructed with the two different resolution parameters. This ratio is found to be similar to the measurement in pp collisions at root s = 7 TeV and to the expectations from PYTHIA pp simulations and NLO pQCD calculations at root s(NN) = 5.02 TeV. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V
Differential studies of inclusive J/psi and psi (2S) production at forward rapidity in Pb-Pb collisions at root s(NN)=2:76 TeVe
The production of J/psi and psi (2S) was studied with the ALICE detector in Pb-Pb collisions at the LHC. The measurement was performed at forward rapidity (2.5 LT y LT 4) down to zero transverse momentum (p(T)) in the dimuon decay channel. Inclusive J/psi yields were extracted in different centrality classes and the centrality dependence of the average p(T) is presented. The J/psi suppression, quantified with the nuclear modification factor (R-AA), was measured as a function of centrality, transverse momentum and rapidity. Comparisons with similar measurements at lower collision energy and theoretical models indicate that the J/psi production is the result of an interplay between color screening and recombination mechanisms in a deconfined partonic medium, or at its hadronization. Results on the psi(2S) suppression are provided via the ratio of psi(2S) over J/psi measured in pp and Pb-Pb collisions.ALICE Collaboration (ukupan broj autora: 990
Opting for Living-Apart-Together and Cohabitation Relationships in people 50+: A Longitudinal Analysis
Despite a growing body of research on later-life relationships, there are still only a limited number of explorative longitudinal studies that have investigated the factors responsible for the establishment of either a Living-Apart-Together (LAT) arrangement or a cohabitation relationship. Two waves of data collection by the Survey of Health, Ageing and Retirement in Europe (2014/2015-2017; N= 12,155; Mage=71.96; 76.3% women) were analyzed with a special focus on family, dwelling, and financial constraints. Those who were male, younger, and had more children were more likely to enter into a LAT arrangement or a cohabitation relationship than to remain unpartnered. More rooms and fewer years spent in the accommodation raised the odds to partner. LAT persons were slightly older than those in cohabitation relationships. No other factors influenced the form of living arrangement, which indicates that factors other than financial constraints and family responsibilities affect later-life LAT or cohabitation relationship formation.Despite a growing body of research on later-life relationships, there are still only a limited number of explorative longitudinal studies that have investigated the factors responsible for the establishment of either a Living-Apart-Together (LAT) arrangement or a cohabitation relationship. Two waves of data collection by the Survey of Health, Ageing and Retirement in Europe (2014/2015-2017; N= 12,155; Mage=71.96; 76.3% women) were analyzed with a special focus on family, dwelling, and financial constraints. Those who were male, younger, and had more children were more likely to enter into a LAT arrangement or a cohabitation relationship than to remain unpartnered. More rooms and fewer years spent in the accommodation raised the odds to partner. LAT persons were slightly older than those in cohabitation relationships. No other factors influenced the form of living arrangement, which indicates that factors other than financial constraints and family responsibilities affect later-life LAT or cohabitation relationship formation
Flow dominance and factorization of transverse momentum correlations in Pb-Pb collisions at the LHC
We present the first measurement of the two-particle transverse momentum differential correlation function, P2 ≡ hΔpTΔpTi=hpTi2, in Pb-Pb collisions at sNN p ¼ 2.76 TeV. Results for P2 are reported as a function of the relative pseudorapidity (Δη) and azimuthal angle (Δφ) between two particles for different collision centralities. The Δϕ dependence is found to be largely independent of Δη for jΔηj ≥ 0.9. In the 5% most central Pb-Pb collisions, the two-particle transverse momentum correlation function exhibits a clear double-hump structure around Δφ ¼ π (i.e., on the away side), which is not observed in number correlations in the same centrality range, and thus provides an indication of the dominance of triangular flow in this collision centrality. Fourier decompositions of P2, studied as a function of the collision centrality, show that correlations at jΔηj ≥ 0.9 can be well reproduced by a flow ansatz based on the notion that measured transverse momentum correlations are strictly determined by the collective motion of the system
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