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BACKGROUND Growing attention has been paid in recent decades to the effects on male reproduction of occupational exposures to toxic agents. There is strong evidence that high level exposure to lead, i. e. blood lead level (PbB) > 70 microg/dl, is associated with male infertility and some reports suggest an effect even at lower PbB (i. e. < 50 microg/dl).(More)
An ac/dc power conversion system suitable for traction drives supplied by an ac feeder line is considered. In order to work out a simple procedure for the preliminary design of the conversion system, some simplifying hypotheses are made. These hypotheses allow a simple analysis of the overall steady-state behavior of the power conversion system. In this way(More)
OBJECTIVE To assess the effects of both autologous and homologous blood transfusion on the incidence of infective complications after elective operations for colorectal cancer. DESIGN Prospective open study. SETTING University hospital, Italy. INTERVENTIONS Recording of variables known to influence the development of infection. MAIN OUTCOME MEASURES(More)
Several techniques were presented in the literature in order to perform accurate tracking of frequencies for different purposes. Most of them are modified versions of the traditional discrete Fourier transform (DFT) or other spectrum-estimation techniques. This paper presents a procedure based on the statistical analysis of the current signal in the time(More)
Nowadays speed-sensorless electromechanical drives are feasible for many applications. The elimination of the mechanical transducer increases reliability, reducing costs. As far as synchronous machine drives are concerned, this issue is critical since the rotor position is fundamental to derive the proper switching sequence. If an SRM is used as an actuator(More)
Diagnostic techniques of electrical faults for induction machines are usually based on spectral analysis of stator currents. Hence large time acquisition period are mandatory in order to achieve high frequency resolution. Moreover, a sharp knowledge of supply frequency and slip are required in order to monitor the spectrum lines specifically linked to(More)
A series of hydroxycholan-24-amines was synthesized; the carboxyl group of starting unconjugated bile acids was transformed into a basic moiety [-NH2, -NHCH3, -N(CH3)2, or -NHCH2C6H5] at C-24. Solubilities, acidities, partition coefficients, and critical micellar concentrations were measured and compared with those of the corresponding bile acids. Because(More)
  • A. Bellini
  • 2007
Motor current signature analysis is the reference method for the diagnosis of induction machines. However, it features some drawbacks, as it is bound to steady-state conditions, and fault signatures may be created by different overlapping phenomena. This paper presents a full-time domain-based method for the quantitative evaluation of electrical faults in(More)
The paper takes into consideration three-phase four-leg inverters used to supply unbalanced loads without using a transformer. In literature different three-dimensional modulation techniques, requiring complex mathematical algorithms are proposed for this kind of inverter. The paper suggests a different approach, based on the separation of the control of(More)