BODY AERODYNAMICS: CONTRIBUTION TO LONG JUMP PERFORMANCE

A mathematical model of a long jumper flight dynamics is proposed. The model incorporates the factor of the full aerodynamic force exerted during the flight phase under varying conditions. The full aerodynamic force is applied to the body at some angle to the vector of air speed and can be represented as vector sum of drag and lift forces. The magnitudes of the drag and lift components, as well as their role in the length of the jump are affected by a number of parameters, such as flight kinematics, wind velocity, mean altitude, etc., which vary from athlete to athlete, between attempts and competition grounds. Analysis of the video recordings of the jumps of the leading long jumpers were processed using computerized image processing schemes. As the result, the kinematics of the jumps and the aerodynamics of the athletes' bodies at various stages of the flight phase, drag and lift quotients were calculated as the function of the angle of attack of the body, using regression analysis approach. The results obtained make possible determining the influence of the wind velocity and mean altitude. Based on this, the forecast of results and comparable values, derived from the results obtained under specific conditions can be performed. Table gives the results of numerical analysis for three high performance attempts in trial conditions and recalculated to the normalized conditions (zero wind /zero mean elevation). The comparison of the actual and normalized data indicates that the absolute value of the results in long jump during last 24 years might be reconsidered. As another application of the developed model, a series of iso-energetic trajectories was emulated, in order to enhance the performance by optimizing the flight aerodynamics under average conditions

Multi-cutter turning process stability analysis

This work displays results of a modelling-based investigation a process of multi-cutter turning process focusing on the stability of nominal steady-state case. The modelling is based on the new surface formation equations, on the equations of motion and on a rational fraction cutting law. The influence of the parameters of the system on the stability of the steady cut is analyzed

Water data analysis: data reduction from beam and ITC info

After recalling the motivation for the analysis of water data, the first stage of data reduction is discussed. This data reduction is based on the selection of protons using beam detector data and ITC information. The resolution of the interaction time in the target which serves as reference for time-of-flight measurement of secondaries, is determined with stable beam optics to be 77 ps, otherwise 106 ps. Cuts, their selection efficiency, event numbers, purity of the data sample after cuts, and some ITC characteristics are presented

Revisiting the 'LSND anomaly' II: critique of the data analysis

This paper, together with a preceding paper, questions the so-called 'LSND anomaly': a 3.8 sigma excess of antielectronneutrino interactions over standard backgrounds, observed by the LSND Collaboration in a beam dump experiment with 800 MeV protons. That excess has been interpreted as evidence for the antimuonneutrino to antielectronneutrino oscillation in the \Deltam2 range from 0.2 eV2 to 2 eV2. Such a \Deltam2 range is incompatible with the widely accepted model of oscillations between three light neutrino species and would require the existence of at least one light 'sterile' neutrino. In a preceding paper, it was concluded that the estimates of standard backgrounds must be significantly increased. In this paper, the LSND Collaboration's estimate of the number of antielectronneutrino interactions followed by neutron capture, and of its error, is questioned. The overall conclusion is that the significance of the 'LSND anomaly' is not larger than 2.3 sigma.Comment: 30 pages, 16 figures, 6 table

Why the paper CERN-PH-EP-2009-015 (arXiv:0903.4762) is scientifically unacceptable

The paper CERN-PH-EP-2009-015 (arXiv:0903.4762) by A. Bagulya et al. violates standards of quality of work and scientific ethics on several counts. The paper contains assertions that contradict established detector physics. The paper falls short of proving the correctness of the authors' concepts and results. The paper ignores or quotes misleadingly pertinent published work. The paper ignores the fact that the authors' concepts and results have already been shown wrong in the published literature. The authors seem unaware that cross-section results from the 'HARP Collaboration' that are based on the paper's concepts and algorithms are in gross disagreement with the results of a second analysis of the same data, and with the results of other experiments.Comment: 8 pages, 3 figure

Cross-sections of large-angle hadron production in proton- and pion-nucleus interactions VII: tin nuclei and beam momenta from \pm3 GeV/c to \pm15 GeV/c

We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary tin target, of proton and pion beams with momentum from \pm3 GeV/c to \pm15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. Cross-sections on tin nuclei are compared with cross-sections on beryllium, carbon, copper, tantalum and lead nuclei.Comment: 68 pages, 13 figure