Diagnosis of Centrifugal Pump Faults Using Vibration Methods

Pumps are the largest single consumer of power in industry. This means that faulty pumps cause a high rate of energy loss with associated performance degradation, high vibration levels and significant noise radiation. This paper investigates the correlations between pump performance parameters including head, flow rate and energy consumption and surface vibration for the purpose of both pump condition monitoring and performance assessment. Using an in-house pump system, a number of experiments have been carried out on a centrifugal pump system using five impellers: one in good condition and four others with different defects, and at different flow rates for the comparison purposes. The results have shown that each defective impeller performance curve (showing flow, head, efficiency and NPSH (Net Positive Suction Head) is different from the benchmark curve showing the performance of the impeller in good condition. The exterior vibration responses were investigated to extract several key features to represent the healthy pump condition, pump operating condition and pump energy consumption. In combination, these parameter allow an optimal decision for pump overhaul to be made [1]

A new method of vibration analysis for the diagnosis of impeller in a centrifugal pump

Centrifugal pumps are widely used in many important industries such as power generation plants, chemical processes and petroleum refiners. The condition monitoring of centrifugal pumps is highly regarded by many researchers and users to minimize unexpected break-downs. Impellers are the core parts of pumps but often appear early damages due to flow cav-itation and erosion. This paper investigates a new approach to monitoring the conditions of impellers using surface vibration with advanced signal analysis. As overall vibration respons-es contain high level of broadband noises due to cavities and turbulences, noise reduction is critical to develop reliable and effective features. However, considering the modulation effect between rotating shaft and blade passing components, a modulation signal bispectrum (MSB) method is employed to extract these deterministic characteristics of modulations, which is different from previous researches in that broadband random sources are often used. Experi-mental results show that the diagnostic features developed by MSB allow impellers with inlet vane damages and exit vane faults to be identified under different operating conditions

The investigation of motor current signals from a centrifugal pump for fault diagnosis

In this paper, motor current signals from electrical control systems, rather than installing additional measurement systems, are characterised for the fault diagnosis of centrifugal pumps. Modulation signal bispectrum (MSB) analysis is applied to reveal the weak nonlinear characteristics of current signals when the pump with different impeller faults operates under a wide range of flow conditions. Experimental results show that two static features including the amplitude at supply frequency and the frequency value of bar-passing frequency can be based on to diagnose impeller defects on exit vane tips and inlet vane tips. In addition, the dynamic parameter of sidebands at vane-passing frequency can also be a good indicator for differentiating between the faults

A critical review of complementary and alternative medicine use by women with cyclic perimenstrual pain and discomfort: a focus upon prevalence, patterns and applications of use and users' motivations, information seeking and self-perceived efficacy

© 2016 Nordic Federation of Societies of Obstetrics and Gynecology Introduction: Complementary and alternative medicine (CAM) is used for treating cyclic perimenstrual pain and discomfort. This critical review examines women's reported CAM use, its perceived effectiveness and information relating to women's attitudes, behaviors, motivations and patterns of CAM use in its treatment. Material and methods: An extensive search of the main medical databases EBSCO, CINAHL, Medline, AMED and SCOPUS, as well as additional hand searches, was conducted. Papers included were confined to those that had been peer-reviewed, written in English and that contained original research into CAM use for cyclic perimenstrual pain and discomfort among adult women. Results: CAM, particularly herbal medicine, nutritional supplements and massage, is widely used for a range of cyclic perimenstrual pain and discomfort symptoms. A large number of CAM modalities are adopted, often simultaneously and with little professional oversight. Women's assessment of efficacy of different CAM modalities is positive, though the majority of users are self-prescribing apparently without professional guidance. Although the uptake of CAM for cyclic perimenstrual pain and discomfort is widespread, few empirical data are available regarding which women are using CAM, their motivations for doing so and, importantly, the sources through which women receive information about CAM. Conclusions: This review highlights the extensive use of (often self-prescribed) CAM in a number of countries to alleviate the widespread symptoms of cyclic perimenstrual pain and discomfort. An understanding of all health care use by women with perimenstrual pain and discomfort is vital to help ensure safe, effective and coordinated health care that can lead to optimal patient outcomes

Stakeholders' perspectives on the regulation and integration of complementary and alternative medicine products in Lebanon: a qualitative study

<p>Abstract</p> <p>Background</p> <p>The regulation of the markets for Complementary and Alternative Medicine (CAM) products presents a global challenge. There is a dearth of studies that have examined or evaluated the regulatory policies of CAM products in the Eastern Mediterranean Region (EMR). We investigate the regulatory frameworks and the barriers for the proper regulation and integration of CAM products in Lebanon, as an example of an EMR country with a weak public infrastructure.</p> <p>Methods</p> <p>We utilized a qualitative study design involving a series of semi-structured interviews with stakeholders of the CAM market in Lebanon. Snowball sampling was used to identify interviewees; interviews continued until the "saturation" point was reached. A total of 16 interviews were carried out with decision makers, representatives of professional associations, academic researchers, CAM product importers, policy makers and a media representative. Interviews were transcribed and thematic analysis of scripts was carried out.</p> <p>Results</p> <p>There was a consensus among all stakeholders that the regulation of the market for CAM products in Lebanon needs to be strengthened. Thematic analysis identified a number of impediments jeopardizing the safety of public consumption and hindering the integration of CAM therapies into mainstream medicine; including: weak infrastructure, poor regulation, ineffective policies and politics, weak CAM awareness and sub-optimal coordination and cooperation among stakeholders. With respect to policy instruments, voluntary instruments (self regulation) were deemed ineffective by stakeholders due to poor awareness of both users and providers on safe use of CAM products. Stakeholders' rather recommended the adoption of a combination of mixed (enhancing public awareness and integration of CAM into medical and nursing curricula) and compulsory (stricter governmental regulation) policy instruments for the regulation of the market for CAM products.</p> <p>Conclusions</p> <p>The current status quo with respect to the regulation of CAM products in Lebanon is not conducive to public safety, nor does it support the integration of CAM products into the healthcare system. The Ministry of Health indeed plays a dominant role in the regulation of these products through a combination of mixed and compulsory policy instruments. Yet, the proper implementation of these regulations requires political resolve coupled with the cooperation of all CAM stakeholders.</p

Perspectives and attitudes of breastfeeding women using herbal galactagogues during breastfeeding: a qualitative study

Some herbal galactagogues have gained reputation and recognition by the public and health professionals as alternative approaches to increase breast milk supply. This study explores the perspectives and attitudes of breastfeeding women towards the use of herbal galactagogues while breastfeeding, their experiences, and why and how they have chosen an alternative option over conventional treatments to enhance breastfeeding performance. This exploratory research was conducted through in-depth semi-structured interviews with women living in Perth, Western Australia, who were using one or more herbal galactagogues during breastfeeding. Purposeful and subsequent snowball sampling methods were employed to recruit participants. All interviews, facilitated by an interview guide, were audio-recorded, then transcribed verbatim. Thematic analysis was used to analyse qualitative data to construct themes and subthemes.The perspectives and attitudes of the 20 participants are classified under three main headings: i) use of herbal medicines during breastfeeding, ii) available herbal medicines resources, and iii) level of breastfeeding support received. Throughout the interviews, participants described how their perseverance and determination to breastfeed, as well as concerns over breastfed infants’ safety with conventional treatments, influenced their choice of therapy. A sense of self-efficacy and autonomy over their own health needs was seen as influential to their confidence level, supported self-empowerment and provided reassurance throughout the breastfeeding journey. There was also a desire for more evidence-based information and expectations of health professionals to provide credible and reliable information regarding the use of herbal medicines during breastfeeding. This study has enhanced our understanding of the perspectives and attitudes of breastfeeding women towards the use of herbal medicines, in particular galactagogues, while breastfeeding. The positive attitudes of breastfeeding women identified in this study highlight the need for further research into evaluating the safety and efficacy of commonly used herbal galactagogues, whilst the negative views on breastfeeding education should be taken into consideration when implementing or improving breastfeeding-related health policies

The use of herbal medicines during breastfeeding: A population-based survey in Western Australia

Background: Main concerns for lactating women about medications include the safety of their breastfed infants and the potential effects of medication on quantity and quality of breast milk. While medicine treatments include conventional and complementary medicines, most studies to date have focused on evaluating the safety aspect of conventional medicines. Despite increasing popularity of herbal medicines, there are currently limited data available on the pattern of use and safety of these medicines during breastfeeding. This study aimed to identify the pattern of use of herbal medicines during breastfeeding in Perth, Western Australia, and to identify aspects which require further clinical research. Methods: This study was conducted using a self-administered questionnaire validated through two pilot studies. Participants were 18 years or older, breastfeeding or had breastfed in the past 12 months. Participants were recruited from various community and health centres, and through advertising in newspapers. Simple descriptive statistics were used to summarise the demographic profile and attitudes of respondents, using the SPSS statistical software. Results: A total of 304 questionnaires from eligible participants were returned (27.2% response rate) and analysed. Amongst the respondents, 59.9% took at least one herb for medicinal purposes during breastfeeding, whilst 24.3% reported the use of at least one herb to increase breast milk supply. Most commonly used herbs were fenugreek (18.4%), ginger (11.8%), dong quai (7.9%), chamomile (7.2%), garlic (6.6%) and blessed thistle (5.9%). The majority of participants (70.1%) believed that there was a lack of information resources, whilst 43.4% perceived herbal medicines to be safer than conventional medicines. Only 28.6% of users notified their doctor of their decision to use herbal medicine (s) during breastfeeding; 71.6% had previously refused or avoided conventional medicine treatments due to concerns regarding safety of their breastfed infants. Conclusions: The use of herbal medicines is common amongst breastfeeding women, while information supporting their safety and efficacy is lacking. This study has demonstrated the need for further research into commonly used herbal medicines. Evidence-based information should be available to breastfeeding women who wish to consider use of all medicines, including complementary medicines, to avoid unnecessary cessation of breastfeeding or compromising of pharmacotherapy