An overview of time-based and condition-based maintenance in industrial application

One of the earliest documented applications of acoustic emission technology (AET) to rotating machinery monitoring was in the late 1960s. Since then, there has been an explosion in research- and application-based studies covering bearings, pumps, gearboxes, engines, and rotating structures. In this paper we present a comprehensive and critical review to date on the application of AET to condition monitoring and diagnostics of rotating machinery.

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Development of Acoustic Emission Technology for Condition Monitoring andDiagnosis of Rotating Machines; Bearings, Pumps, Gearboxes, Engines and RotatingStructures.

In most of the industries related to mechanical engineering, the usage of pumps is high. Hence, the system which takes care of the continuous running of the pump becomes essential. In this paper, a vibration based condition monitoring system is presented for monoblock centrifugal pumps as it plays relatively critical role in most of the industries. This approach has mainly three steps namely feature extraction, classification and comparison of classification. In spite of availability of different efficient algorithms for fault detection, the wavelet analysis for feature extraction and Naive Bayes algorithm and Bayes net algorithm for classification is taken and compared. This paper presents the use of Naive Bayes algorithm and Bayes net algorithm for fault diagnosis through discrete wavelet features extracted from vibration signals of good and faulty conditions of the components of centrifugal pump. The classification accuracies of different discrete wavelet families were calculated and compared to find the best wavelet for the fault diagnosis of the centrifugal pump.

A comparative study of Naïve Bayes classifier and Bayes net classifier for fault diagnosis of monoblock centrifugal pump using wavelet analysis

Monoblock centrifugal pumps are widely used in a variety of applications. In many applications the role of monoblock centrifugal pump is critical and condition monitoring is essential. Vibration based continuous monitoring and analysis using machine learning approaches are gaining momentum. Particularly artificial neural networks, fuzzy logic were employed for continuous monitoring and fault diagnosis. This paper presents the use of C4.5 decision tree algorithm for fault diagnosis through statistical feature extracted from vibration signals of good and faulty conditions.

Vibration based fault diagnosis of monoblock centrifugal pump using decision tree

Comparison of decision tree-fuzzy and rough set-fuzzy methods for fault categorization of mono-block centrifugal pump

Pumps play a significant role in industrial plants and need continuous monitoring to minimise loss of production. To date, there is limited published information on the application of acoustic emission (AE) to incipient pump cavitation. This paper presents a case study where AE has been applied for detecting incipient cavitation and determining the best efficiency point (BEP) of a 60 kW centrifugal pump. Results presented are based on net positive suction head (NPSH) and performance tests. In conclusion, the AE technique was shown to offer early detection of incipient cavitation, furthermore, the technique has demonstrated the ability to determine the BEP of a pump.

The application of acoustic emission for detecting incipient cavitation and the best efficiency point of a 60 kW centrifugal pump: case study

Background: Self-medication is defined by the World Health Organization (WHO) as the selection and use of medicines by individuals to treat self-recognized illnesses or symptoms [4]. Use of traditional eye medicines or ophthalmic medicines without the supervision of an ophthalmologist may have adverse effects on the patient’s visual outcome. It is well known that this attitude and practice carries pharmacological and toxicological risks, such as a delayed diagnosis or inappropriate treatment, causing side-effects, intoxication or harmful drug interactions, which can aggravate the individual’s condition and eventually negatively impact the patient’s visual prognosis [5]. Materials and methods: The study was a cross-sectional study. All data was collected using an online self-designed questionnaire that contained demographic data, such as the patient’s age, gender and level of education. There were also questions regarding the knowledge, attitude and practice of using over-the-counter (OTC) eye medication and TEM use among the Saudi population living in the Kingdom of Saudi Arabia. Result: The study sample included 894 respondents. Results showed that in the past 12 months, only 6.82% of respondents used eye medications without visiting an ophthalmologist. The most common self-prescribed medications were anti-allergic and antibiotics. The results revealed that 148 respondents had previously used TEMs (16.4%). The majority of respondents (86.6%) preferred medications over TEM to treat eye diseases. Key words: self-medication, traditional eye medication, Saudi Arabia, ophthalmology, eye

Prevalence of self-medication use, and the attitude and practices toward traditional eye medicines regarding eye symptoms

Objectives: To assess the knowledge and attitudes of physicians of different specialties, including psychiatrists, regarding forensic psychiatry to determine whether further modification or training is needed in the psychiatry residency program. Methods: This cross-sectional study was carried out using a 3-page, 3-section questionnaire containing 21 questions disseminated randomly online via Google forms using social media platforms. The 482 participants were residents, specialists, and consultants of various specialties. The study was conducted between September 2020 and August 2021 in various tertiary hospitals across Saudi Arabia. Results: A total of 482 physicians were recruited. The most common age group was 25-35 years, comprising mostly Saudis (62.4%). Based on the results, “poor” and “good” knowledge of forensic psychiatry was identified in 89% and 11% of the physicians, while “negative” and “positive” attitudes were identified in 16.4% and 83.6% of the physicians. Conclusion: Although the perspective of physicians regarding forensic psychiatry was found to be positive, their knowledge of the topic seems to be lacking.

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L. Alfayez

Papers

The application of acoustic emission for detecting incipient cavitation and the best efficiency point of a 60 kW centrifugal pump: case study

Prevalence of self-medication use, and the attitude and practices toward traditional eye medicines regarding eye symptoms

Knowledge and attitudes of physicians toward forensic psychiatry in Saudi Arabia