Search results

Reliability study plays a significant role in supporting the operation of any machinery working in a dynamic and harsh environment. This quality is inherently uncertain and a stochastic variable of any system. This study will be beneficial for designing an appropriate maintenance schedule, reducing unplanned production downtime and reducing maintenance cost of electrical motor operated particularly in dynamic and harsh environmental industries.

This study focused on the effects of operating conditions (OCs) on the operational reliability and remaining useful life (RUL) of machinery. A probabilistic graphical method called Bayesian network (BN) was used for studying the effect of OCs on the system performance. The developed methodology has been demonstrated by analyzing the operational reliability and predicting the RUL of electrical motors operated in a heavy mining machinery.

The failure probabilities estimated from the historical data of the motor system are failure likelihood, and OCs are the evidence in the developed BN model. It has been observed that the performance and RUL of the motor are significantly influenced by OCs and maintenance. A threshold value of reliability at which the motor system requires maintenance or replacement has been proposed to guide management in decision making.

The Bayesian approach for studying the covariate of motor reliability and RUL estimation is a novel approach. This study will be beneficial for designing an appropriate maintenance schedule, reducing unplanned production downtime and reducing maintenance cost of electrical motor operated particularly in dynamic and harsh environmental industries.

The purpose of this paper is to propose a new measure for criticality analysis of different components of a production plant, called cost‐effective importance measure (CEIM) that considers the component's performance, system structure and economic aspects.

In this work, an explorative literature study covering the concept of importance measure and criticality analysis has been carried out on contemporary literature. The literature study shows that the commonly used importance measures consider the probability of failure of a component and systems structure, and ignore the effect or severity of failures, which is an important factor in engineering decision making. It is not clear how to use the concept of importance measure in combination with cost parameter. Hence, a cost‐effective importance measure (CEIM) is defined and a case study is presented, to demonstrate the application of the proposed importance measure.

The paper indicates that CEIM useful for the analysis of production plants where reliability and cost of break down are of paramount importance.

The concept of CEIM is demonstrated using only a case study of a belt conveyor system in the underground mine of Singareni Coal Company Ltd. However, the concept of CEIM can be used in other area.

The concept of CEIM can be a handy and effective tool for scheduling of inspection, maintenance and fault diagnosis and these activities can be carried out as per the rank of the components to maximize the benefits in skilled manpower crunch. It also indicates that the upgradation of the production plant's performance can also be done by improving performance of components with relatively large CEIM values.

In this paper, the concept of importance measure is extended to include the effect of severity of failures and cost parameter in the criticality analysis.

Oral health is an integral part of general health. Different population groups have been assessed for oral health status in India, but still, many have been neglected; one such group is the prisoners. The prison population is a unique and challenging one with many health problems, including poor oral health, which may be due to lack of knowledge about good oral health practices. This study aims to assess effectiveness of oral health education on oral health knowledge, attitude and practices and oral hygiene status among the male prison inmates of central jail in Kolkata, India.

An interventional study was done among 240 male convicts. The data was elicited using a structured proforma; oral health status was assessed by recording OHI-S index, and the severity of gingivitis was assessed by recording the gingival index. Oral health education was delivered by using audio-visual aid. Oral health knowledge, attitude, practices and oral hygiene and gingival status were reassessed among the inmates before and after dental education at the end of three and six months.

A significant change in oral health knowledge, attitude and practices was seen, which in turn resulted in an appreciable decrease in the mean gingival index score (1.73 ± 0.382 to 1.20 ± 0.321) and OHI-S (3.31 ± 0.815 to 2.57 ± 0.551) in all the inmates after oral health education program over the period of time.

The oral health education with reinforcement proved to be an effective tool to instil good oral hygiene practices in the inmates.