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Article
Publication date: 2 March 2015

Jie Zhang, Jing Liu, Qian Hu, Feng Huang, ZhaoYang Cheng and JunTao Guo

The aim of this paper was to clarify the influence of tensile stress on the electrochemical behavior of X80 steel in a simulated acid soil solution and attempt to…

Abstract

Purpose

The aim of this paper was to clarify the influence of tensile stress on the electrochemical behavior of X80 steel in a simulated acid soil solution and attempt to understand mechanistic aspects of the corrosion behaviors of X80 under these conditions.

Design/methodology/approach

The electrochemical behavior of X80 steel at various tensile stresses was investigated in a simulated acid soil solution using electrochemical impedance spectroscopy, potentiodynamic scan measurements and surface analysis techniques.

Findings

The results show that as tensile stress was increased, the open-circuit potential decreased, the reaction activity increase, the reaction resistance (Rct)value became smaller by degrees, the corrosion product film resistance (Rf) first decreased and then increased and polarization current densities changed conversely. The corrosion product film was compact and continuous under the low stress, whereas it was relatively loose under high-stress conditions. Tensile stress promotes the movement of dislocations, which become active points when they move to the steel surface. The increase in the number of active points enhances the anodic dissolution rate and promotes the formation of corrosion product film whose blocking effect can decrease the dissolution rate. The corrosion rate of the specimen is determined by these two effects.

Originality/value

This research provides an essential insight into the mechanism of the electrochemical behavior of X80 steel in acid soil environments.

Details

Anti-Corrosion Methods and Materials, vol. 62 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 22 June 2012

Jie Gong, Zhifeng Zhang, Zhaoyang Zhu, Jun Wan, Niannian Yang, Fang Li, Huiling Sun, Weiping Li, Jiang Xia, Dunjin Zhou and Xinguang Chen

The paper seeks to report data on cigarette smoking, anti‐smoking practices, physicians' receipt of anti‐smoking training, and the association between receipt of the…

Abstract

Purpose

The paper seeks to report data on cigarette smoking, anti‐smoking practices, physicians' receipt of anti‐smoking training, and the association between receipt of the training and anti‐smoking practice among physicians in Wuhan, China.

Design/methodology/approach

Participants were selected through the stratified random sampling method. The questionnaires were completed by the sampled physicians and the response rate of the survey was 98.1 percent.

Findings

Among the total sample, 11 percent were current smokers. Significantly more male physicians than female physicians were current smokers (31.6 vs 0.9 percent, p<0.001). In total, 41 percent of physicians always or often asked patients about smoking habits, and 61 percent of them often advised patients to quit. Receiving anti‐tobacco training significantly increased the likelihood for physicians to ask patients about smoking (odd ratio=2.55, p<0.001) and to advise patients against smoking (odd ratio=4.05, p<0.001) with and without controlling gender, age, education, type of hospital and medical services specialty.

Practical implications

More effort should be devoted to training for physicians with focus on anti‐smoking practice and smoking cessation counseling in addition to assist physicians themselves to quit smoking.

Originality/value

The findings of this study update the data regarding cigarette smoking among physicians in Wuhan, China, and their practice of anti‐tobacco counseling. It indicates that it is very important to provide the training regarding anti‐smoking counseling among physicians.

Details

Health Education, vol. 112 no. 4
Type: Research Article
ISSN: 0965-4283

Keywords

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Article
Publication date: 22 June 2012

Dunjin Zhou, Yaqiong Yan, Huihong Yu, Qinghua Xia, Niannian Yang, Zhifeng Zhang, Zhaoyang Zhu, Fang Li and Jie Gong

This study aims to examine whether, in the opinion of patients selected in 13 hospitals of Hubei province, China, hospitals are smoke free. Patients were also asked…

Abstract

Purpose

This study aims to examine whether, in the opinion of patients selected in 13 hospitals of Hubei province, China, hospitals are smoke free. Patients were also asked whether their physicians had inquired about their smoking status.

Design/methodology/approach

Patients were recruited through an intercept method (i.e. stopped by the interviewer while in the hospital); data were collected through interviews, with a response rate of 96.1 percent.

Findings

Among the intercepted patients, 48.3 percent reported having seen people smoking in hospitals; 22.3 percent had seen a doctor and/or nurse smoking; 23.8 percent had smelled tobacco in hospitals; 68.4 percent reported having seen “no‐smoking” signs in hospital settings; 42.6 percent reported having been asked about smoking status in their latest visit to a doctor and 23.8 percent reported receiving tobacco cessation counseling. Compared to hospitals in large cities, patients from medium/small city hospitals reported significantly higher levels of cigarette smoking among physicians, and poorer implementation of regulations for a smoking‐free hospital, and less smoking cessation counseling by physicians.

Originality/value

Findings of this study point to the need for greater efforts to be made in promoting a smoke free environment in hospitals, as well as encouraging physicians to provide more smoking cessation counseling to smoking patients, particularly physicians in small and medium hospitals.

Details

Health Education, vol. 112 no. 4
Type: Research Article
ISSN: 0965-4283

Keywords

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Article
Publication date: 7 October 2013

Marcello Braglia, Davide Castellano and Marco Frosolini

The purpose of this paper is to present a reliability centered maintenance (RCM) embedded integer linear programming approach (suited to the budget monetary resources…

Abstract

Purpose

The purpose of this paper is to present a reliability centered maintenance (RCM) embedded integer linear programming approach (suited to the budget monetary resources allocation task) to the maintenance strategies mix selection for an industrial plant equipment.

Design/methodology/approach

The developed approach allows to determine the optimal maintenance strategies mix for a set of equipment in a more quantitative way than the classic RCM approach. The proposed model takes into account, for each potential failure determined using the FMECA and for each admissible strategy, the costs and the potential risk priority number (RPN) reduction. Finally, an industrial case concerning an Italian paper-mill plant is reported to demonstrate the effectiveness of the approach presented.

Findings

The paper finds that the application of the proposed approach allows to optimally allocate the budget monetary resources, determining which suitable maintenance practice apply to each failure, taking into account the costs of each strategy and the potential reduction of the RPN.

Practical implications

The proposed model permits to assign (during the budget monetary resources allocation task) to each failure the optimal strategy, among a set of suitable maintenance practices, considering the costs and the estimated RPN reduction.

Originality/value

The paper proposes a completely new RCM embedded approach to the maintenance strategies selection, in order to optimally allocate the budget monetary resources. This model overcomes the limits of the traditional RCM approach, taking into account quantitative aspects, i.e. the compatibility constraint between failures and policies, the maintenance strategies costs, and the RPN estimated reduction.

Details

International Journal of Quality & Reliability Management, vol. 30 no. 9
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 11 January 2019

Abdul Hameed, Syed Asif Raza, Qadeer Ahmed, Faisal Khan and Salim Ahmed

The purpose of this paper is to develop a decision support tool for risk-based maintenance scheduling for a large heavily equipped gas sweetening unit in a Liquefied…

Abstract

Purpose

The purpose of this paper is to develop a decision support tool for risk-based maintenance scheduling for a large heavily equipped gas sweetening unit in a Liquefied Natural Gas (LNG) plant. Two conflicting objectives, i.e., total maintenance cost and the reliability, are considered in the tool. The tool is tested with the real plant data and suggests several Pareto-optimal schedules for a decision maker to choose from. The financial impacts are assessed.

Design/methodology/approach

A bi-objective scheduling optimization model is developed for maintenance scheduling using a risk-based framework. The model is developed integrating genetic algorithm and simulation-based optimization to find Pareto-optimal schedules. The model delivered true Pareto front optimal solutions for given plant-specific data. The two conflicting objectives: the minimization of total expenditures incurred on maintenance-related activities and improving the total reliability are considered.

Findings

For large and complex processing facilities such as LNG plant, a shutdown of facility generates a significant financial impact, resulting in millions of dollars in production loss. The developed risk-based equipment selection strategy helps to minimize such an event of production loss by generating a thorough maintenance strategy for inspection, repair, overhaul or replacement schedule of the unit without initiating the shutdown. The proposed model has been successfully applied to obtain an optimize maintenance schedule for a gas sweetening unit.

Research limitations/implications

A future work may consider the state-dependent models for various failure modes that will result in obtaining a better representation of the model. The proposed scheduling can further be extended to multi-criteria scheduling including availability, resource limitation and inflationary condition. A comparative analysis with other meta-heuristic techniques such as harmony search algorithm, tabu search, and simulated annealing will further help in confirming the schedule obtained from this application.

Practical implications

Maintenance scheduling using a conventional approach for special equipment generally does not consider the conflicting objectives. This research addresses this aspect using a bi-objective model. The usefulness of risk-based method is to assist in minimizing the financial and safety risk exposure to the operating companies, but some variation in results is expected due to varying risk matrix for different organizations.

Social implications

Managing two objectives, i.e., minimizing the cost of maintenance-related activities, while at the same time maximizing the overall reliability dramatically, helps in mitigating adverse safety and financial risk due to fires, explosions, fatality and excessive maintenance cost.

Originality/value

Research develops a decision support tool for managing conflicting objectives for an LNG process. This research highlights the impact of utilizing the simulation-based approach coupled with risk-based equipment selection for complex processing unit or plant maintenance scheduling optimization.

Details

Journal of Quality in Maintenance Engineering, vol. 25 no. 1
Type: Research Article
ISSN: 1355-2511

Keywords

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