Condition monitoring indicators for pitting detection in planetary gear units

In industrial field, there is an increasing demand for monitoring systems enabling predictive maintenance programs. In this context, the present work concerns the monitoring of distributed wear (pitting) in planetary gearboxes. For this purpose, some metrics of the synchronous average of the vibration signal, based on the statistical moment of the fourth order, are present in literature; in this paper, a new indicator is proposed, namely NA4mod. The effectiveness of this metric in identifying the early stage of pitting has been evaluated by conducting an accelerated life test of about 700 hours on a test bench using a back-to-back configuration. The paper introduces the proposed metric, describes the test, presents and dis-cusses the results. Metric NA4mod exhibits satisfactory capability to detect pitting with better reliability than other metrics in literature. In addition, the metric is shown to be sensitive to both early stage damage and pitting severity in the final stage. Results are verified by means of wavelet-transform analysis

Computed tomography of solitary fibrous tumor of the pleura abutting the mediastinum: A diagnostic challenge

Background: Solitary fibrous tumor of the pleura (SFTP) arising from the mediastinal pleura may be confused with primary mediastinal tumors. We studied the computerized tomographic (CT) findings of patients with SFTP that could suggest a diagnosis of SFTP. Materials and Methods: At our hospital from January 1995 to June 2012, 39 patients with histologically confirmed SFTP were surgically treated; seven of them abutting the mediastinal pleura. The study group included seven patients aged between 53 and 81 years. Baseline CT scans were retrospectively reviewed to identify radiological findings suggestive of SFTP including: (1) smooth and sharply delineated contours; (2) obtuse, acute, or tapering angles between the lesion and the mediastinum depending on the size; (3) homogeneous soft-tissue attenuation; (4) “geographic pattern” due to the contemporary presence of large vessels, necrosis, and calcifications; (5) displacement of the lung parenchyma; (6) presence of a cleavage plane; and (7) absence of lymphadenopathy or pleural methastasis. Results: All tumors formed acute angles with the pleura. Six out of the seven presented smoothly tapering margins, three had a “geographic pattern” of attenuation and displaced the anterior junction line; one showed an outside junction line development. Four cases had a clear pleural origin. Conclusions: The possibility of SFTP should be taken into account when a mass abuts the mediastinum projecting inside the thoracic cavity in the presence of an intense and “geographical pattern” of enhancement without lymphoadenopathy or pleural metastasis. These findings assume greater significance in the presence of discrepancy between the size of the lesion and the clinical presentation

Motor Current Cyclic-Non-Stationary Analysis for Bearing Diagnostic

The Motor Current Signature Analysis (MCSA) is a research area focused on the diagnosis of components of electric motors based on post-processing of the current signal mainly. In particular, the bearing diagnostics is based on two different assumptions: the fault on the bearing causes a vibration of the shaft it supports, so there is an air gap variation between stator and rotor causing a modulation in the current signal; the fault on the bearing hinders the rotation of the shaft, so it can be modeled as an additional loading torque that the motor satisfies increasing the current signal. In this paper, a cyclic-non-stationarity analysis of the motor current is used to assess the status of ball-bearings in servomotors, running at variable speed. Both speed of the motor and motor current are provided by the control loop of the servomotor, that is no external sensors are used. The cyclic nature of the application allows an average of the cyclic-cyclic order maps to increase the signal-to-noise ratio. The proposed technique is successfully applied to both healthy and faulty bearings

E835 at FNAL: Charmonium Spectroscopy in pˉp\bar p p Annihilations

I present preliminary results on the search for $h_c$ in its $\eta_c\gamma$ and $J/\psi\pi^0$ decay modes. We observe an excess of \eta_c\gamma$events near 3526 MeV that has a probability${\cal P} \sim 0.001$to arise from background fluctations. The resonance parameters are$M=3525.8 \pm 0.2 \pm 0.2 $MeV,$\Gamma\leq$1 MeV, and$10.6\pm 3.7\pm3.4(br) < \Gamma_{\bar{p}p}B_{\eta_c\gamma} < 12.8\pm 4.8\pm4.5(br) $eV. We find no event excess within the search region in the$J/\psi\pi^0$ mode.Comment: Presented at the 6th International Conference on Hyperons, Charm and Beauty Hadrons (BEACH 2004), Chicago(Il), June 27-July 3,200

Interference Study of the chi_c0 (1^3P_0) in the Reaction Proton-Antiproton -> pi^0 pi^0

Fermilab experiment E835 has observed proton-antiproton annihilation production of the charmonium state chi_c0 and its subsequent decay into pi^0 pi^0. Although the resonant amplitude is an order of magnitude smaller than that of the non-resonant continuum production of pi^0 pi^0, an enhanced interference signal is evident. A partial wave expansion is used to extract physics parameters. The amplitudes J=0 and 2, of comparable strength, dominate the expansion. Both are accessed by L=1 in the entrance proton-antiproton channel. The product of the input and output branching fractions is determined to be B(pbar p -> chi_c0) x B(chi_c0 -> pi^0 pi^0)= (5.09 +- 0.81 +- 0.25) x 10^-7.Comment: 4 pages, 4 figures, Accepted by PRL (July 2003

Precision measurements of the total and partial widths of the psi(2S) charmonium meson with a new complementary-scan technique in antiproton-proton annihilations

We present new precision measurements of the psi(2S) total and partial widths from excitation curves obtained in antiproton-proton annihilations by Fermilab experiment E835 at the Antiproton Accumulator in the year 2000. A new technique of complementary scans was developed to study narrow resonances with stochastically cooled antiproton beams. The technique relies on precise revolution-frequency and orbit-length measurements, while making the analysis of the excitation curve almost independent of machine lattice parameters. We study the psi(2S) meson through the processes pbar p -> e+ e- and pbar p -> J/psi + X -> e+ e- + X. We measure the width to be Gamma = 290 +- 25(sta) +- 4(sys) keV and the combination of partial widths Gamma_e+e- * Gamma_pbarp / Gamma = 579 +- 38(sta) +- 36(sys) meV, which represent the most precise measurements to date.Comment: 17 pages, 3 figures, 3 tables. Final manuscript accepted for publication in Phys. Lett. B. Parts of the text slightly expanded or rearranged; results are unchange

The UA9 experimental layout

The UA9 experimental equipment was installed in the CERN-SPS in March '09 with the aim of investigating crystal assisted collimation in coasting mode. Its basic layout comprises silicon bent crystals acting as primary collimators mounted inside two vacuum vessels. A movable 60 cm long block of tungsten located downstream at about 90 degrees phase advance intercepts the deflected beam. Scintillators, Gas Electron Multiplier chambers and other beam loss monitors measure nuclear loss rates induced by the interaction of the beam halo in the crystal. Roman pots are installed in the path of the deflected particles and are equipped with a Medipix detector to reconstruct the transverse distribution of the impinging beam. Finally UA9 takes advantage of an LHC-collimator prototype installed close to the Roman pot to help in setting the beam conditions and to analyze the efficiency to deflect the beam. This paper describes in details the hardware installed to study the crystal collimation during 2010.Comment: 15pages, 11 figure, submitted to JINS

Measurement of the Spin-Dependence of the pbar-p Interaction at the AD-Ring

We propose to use an internal polarized hydrogen storage cell gas target in the AD ring to determine for the first time the two total spin-dependent pbar-p cross sections sigma_1 and sigma_2 at antiproton beam energies in the range from 50 to 450 MeV. The data obtained are of interest by themselves for the general theory of pbar-p interactions since they will provide a first experimental constraint of the spin-spin dependence of the nucleon-antinucleon potential in the energy range of interest. In addition, measurements of the polarization buildup of stored antiprotons are required to define the optimum parameters of a future, dedicated Antiproton Polarizer Ring (APR), intended to feed a double-polarized asymmetric pbar-p collider with polarized antiprotons. Such a machine has recently been proposed by the PAX collaboration for the new Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt, Germany. The availability of an intense stored beam of polarized antiprotons will provide access to a wealth of single- and double-spin observables, thereby opening a new window on QCD spin physics.Comment: 51 pages, 23 figures, proposal submitted to the SPS committee of CER