Current/Voltage-Based Detection of Faults in Gears Coupled to Electric Motors

Gears form a critical part of many electromechanical systems. Since gear faults cause vibrations, and vibration-based diagnostics are very reliable, this has traditionally been the most commonly used approach to detecting gear faults. However, it is expensive due to the use of high-priced accelerometers and sensor wiring. This paper proposes an alternative way of detecting faults in gears coupled to brushless dc motors by monitoring either the motor current or voltage. It will be shown that gear faults create unique spectral components in the voltage and current spectrums. The faults investigated include damage to gear teeth and loss of lubrication. Experimental and simulation results demonstrate that motor current/voltage signature analysis is a viable tool to detect these gear faults and is a cheaper alternative than vibration-based fault-detection scheme     

Blockchain Enabled Emperor Penguin Optimizer Based Encryption Technique for Secure Image Management System

Wireless Personal Communications - One of the biggest challenges in autonomous vehicles is processing massive data in real-time and task reliable decisions on time. In order to process data in...     

Evaluation of antitussive agents in man

Methodology to evaluate the efficacy of antitussive drugs rely largely on subjective methods and cough counts. There are few studies in cough due to natural disease especially using objective techniques. This paper presents data from a series of randomized, double blind, placebo controlled clinical trials in cough due to both chronic bronchopulmonary disease and acute upper respiratory tract infections. In these studies, cough was quantified using a standardized and validated computerized system for the acquisition and multidimensional analysis of the cough sound. Key objective parameters like cough counts, intensity, latency and total effort expended were studied. Guaiphenesin and bromhexine showed significant expectorant effects in patients with productive cough due to chronic bronchopulmonary disease. Differences were observed in speed of action, and objective and subjective measures, that probably indicate differences in drug action. More recently, three studies evaluated the antitussive drug dextromethorphan in non-productive cough due to uncomplicated upper respiratory tract infections. Reproducible cough suppressant effects were demonstrated after a single 30 mg dose using objective measures of cough counts, latency and total effort. These results establish the sensitivity and robustness of the cough quantitation methodology in the objective evaluation of cough treatments.     

Bias field inconsistency correction of motion-scattered multislice MRI for improved 3D image reconstruction

A common solution to clinical MR imaging in the presence of large anatomical motion is to use fast multislice 2D studies to reduce slice acquisition time and provide clinically usable slice data. Recently, techniques have been developed which retrospectively correct large scale 3D motion between individual slices allowing the formation of a geometrically correct 3D volume from the multiple slice stacks. One challenge, however, in the final reconstruction process is the possibility of varying intensity bias in the slice data, typically due to the motion of the anatomy relative to imaging coils. As a result, slices which cover the same region of anatomy at different times may exhibit different sensitivity. This bias field inconsistency can induce artifacts in the final 3D reconstruction that can impact both clinical interpretation of key tissue boundaries and the automated analysis of the data. Here we describe a framework to estimate and correct the bias field inconsistency in each slice collectively across all motion corrupted image slices. Experiments using synthetic and clinical data show that the proposed method reduces intensity variability in tissues and improves the distinction between key tissue types.     

An analysis of laminar forced convection film boiling

A study of forced convection film boiling on a horizontal isothermal plate is made using a treatment based on boundary layer theory. For the vapour, the velocity and temperature distributions are obtained from equations of motion and energy. For the liquid layer, the Howarth approximation for flow over a plate is used. Then, by employing interface matching conditions, the significance of the rhμ ratio between the vapour and the liquid on the variation of Nusselt number is examined.