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

Evaluation of IL6, IL10 and VDR alleles distribution in an Italian large sample of subjects affected by chronic periodontal disease

In recent decades, the role played by the immune response to bacteria in the pathogenesis of chronic periodontal disease (PD) has long been studied. Although from the clinical point of view, adequate oral hygiene is essential to ensure a satisfactory response of the host to infections, modulation of the reaction of immune system could be influenced by genetic factors. The aim of the present study was to investigate the distribution of alleles of polymorphisms relevant for chronic periodontitis in a sample of adult subjects affected by chronic PD. The present study was conducted with sample collected in Italian private practice offices from January 2013 to December 2017. The sample included 744 adult patients diagnosed with chronic periodontitis. The inclusion criteria were as follows: age > 18 years, diagnosis of chronic PD. The diagnosis of chronic periodontitis was based on the criteria established by the American Academy of Periodontology. No significant difference in allele distribution among patients from different Italian regions was found. Results, supporting absence of population heterogeneity for the investigated polymorphisms in Italy, suggest similar effect in periodontitis etiology

Beyond Prejudice as Simple Antipathy: Hostile and Benevolent Sexism Across Cultures

The authors argue that complementary hostile and benevolent componen:s of sexism exist ac ro.ss cultures. Male dominance creates hostile sexism (HS). but men's dependence on women fosters benevolent sexism (BS)-subjectively positive attitudes that put women on a pedestal but reinforce their subordination. Research with 15,000 men and women in 19 nations showed that (a) HS and BS are coherenl constructs th at correlate positively across nations, but (b) HS predicts the ascription of negative and BS the ascription of positive traits to women, (c) relative to men, women are more likely to reject HS than BS. especially when overall levels of sexism in a culture are high, and (d) national averages on BS and HS predict gender inequal ity across nations. These results challenge prevailing notions of prejudice as an antipathy in that BS (an affectionate, patronizing ideology) reflects inequality and is a cross-culturally pervasive complement to HS

Prediction of airborne radiated noise from lightly loaded lubricated meshing gear teeth

This paper introduces a novel analytical method for determination of gear airborne noise under lightly loaded conditions, often promoting gear rattle of loose unengaged gear pairs. The system examined comprises a single gear pair, modelled through integrated contact tribology and inertial transient dynamics. Lubricant film thickness, structural vibration and airborne gear noise are predicted and correlated with experimental measurements undertaken in a semi-anechoic environment. Good agreement is noticed between the numerical predictions and the experimental measurements. The presented model is capable of estimating the airborne radiated gear noise levels and the dynamic behaviour of gear pairs under different operating conditions, with superimposed impulsive input speed harmonics