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1 – 10 of 776Long Meng, Min He, Lingjiu Zhou, Jing Yang, Zhengwei Wang and Bryan Karney
– The purpose of this paper is to analyze the cavitation dynamics in the blade channel of a centrifugal pump with a particular focus on the direct influence of the pump’s volute.
Abstract
Purpose
The purpose of this paper is to analyze the cavitation dynamics in the blade channel of a centrifugal pump with a particular focus on the direct influence of the pump’s volute.
Design/methodology/approach
A homogeneous multiphase model, namely the Zwart-Gerber-Belamri cavitation model, is employed to numerically describe the evolution of the process of cavitation within the pump. The RNG k-e turbulence model is applied to analyze the unsteady turbulent flow. A second order implicit formulation is used for the time discretization for the unsteady flow calculation and a finite volume algorithm is used for the space discretization.
Findings
The cavities in the passage exhibit an obvious life cycle which includes initiation, growth, contraction, and separation, and collapse with a frequency corresponding to the impeller rotation frequency under off-design conditions. This phenomenon arises through an alternating interaction between reverse flow with the cavity interface and is associated with the response of the vortex region to the effect of uneven pressure distribution on volute and impeller-tongue interaction.
Originality/value
This study simulated and analyzed the complex transient cavitation flow patterns inside a centrifugal pump and explains the reason for the unsteadiness. This knowledge is instructive in achieving the stable operation of pumps and in trouble shooting rough or cavitating operation.
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Keywords
The purpose of this paper is to highlight an assessment tool that can be used for all information literacy classes.
Abstract
Purpose
The purpose of this paper is to highlight an assessment tool that can be used for all information literacy classes.
Design/methodology/approach
The assessment was designed and data were stored using Google Forms. Questions were basic, general questions about student confidence after attending a library instruction class. The assessment was piloted in the Fall 2015 semester, improved on and reissued in the Spring 2016 semester and is now in its current iteration as a tool to be used by most librarians.
Findings
The first two implementations were successful, but issues arose in distribution and in the type of questions. Tweaks to the distribution that would work in any computer lab on any campus were beneficial to librarians and students. The content of the questions were also modified after the first two implementations; questions about recalling resources were condensed and changed to questions on what the students learned and what they were still unsure of. All implementations showed positive results from the students on their confidence level after library instruction.
Originality/value
This tool and the implementation methods are versatile enough to be used at any kind of institution and with any general learning objective. Assessment is essential in library instruction; this tool provides a way for all librarians to quickly assess their class without taking much additional class time. In addition to the individual librarian, this is also useful for reporting statistics to the college administration if data are needed on the assessment of library instruction.
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Lifu Li and Kyeong Kang
E-entrepreneurship is developed based on digital platforms, having specific technical opportunities, such as the interactive ecosystem, fast payment method and online store…
Abstract
Purpose
E-entrepreneurship is developed based on digital platforms, having specific technical opportunities, such as the interactive ecosystem, fast payment method and online store function, without strict requirements for online entrepreneurs. Considering China’s e-entrepreneurship environment and cultural background, this paper aims to analyse individuals’ e-entrepreneurship motivation based on the capability–opportunity–motivation–behaviour (COM-B) behaviour changing theory.
Design/methodology/approach
Through testing 602 samples based on the partial least squares path modelling and variance-based structural equation modelling, the factors from the opportunity and capability units positively affect individuals’ e-entrepreneurship motivation. Meanwhile, because of the economic and social environmental differences between China’s urban and rural regions, this study promotes the multi-group analysis based on individuals’ regional backgrounds.
Findings
First, as opportunity factors, technical and policy opportunities have significantly positive relationships with individuals’ e-entrepreneurship motivation. Second, entrepreneurial and cultural capabilities are essential for Chinese entrepreneurs while making an entrepreneurial decision. Third, because of the e-entrepreneurial environment difference and educational system gap, entrepreneurial capability exerts a greater influence on the e-entrepreneurship motivation for Chinese individuals from urban regions, and cultural capability exerts a higher impact on the e-entrepreneurship motivation for Chinese individuals from rural regions.
Originality/value
Whilst the phenomenon of e-entrepreneurship is emerging as a popular entrepreneurship area of study, little research has systematically explored individuals’ e-entrepreneurial motivation and analysed influencing factors from macro and minor aspects. According to the COM-B behaviour changing theory, this paper discovers influencing factors from environmental opportunity and personal capability units, and it is helpful to present individuals’ attitudes to the platform-based business model.
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The purpose of this paper is to present an organized review of existing research on reconfigurable manufacturing system (RMS). The paper considers majority of the prominent…
Abstract
Purpose
The purpose of this paper is to present an organized review of existing research on reconfigurable manufacturing system (RMS). The paper considers majority of the prominent research articles in the domain of RMS published ever since RMS was envisaged in 1997.
Design/methodology/approach
The paper systematically reviews, classifies and analyses the published literature on postulations and design of RMSs. The general observations from the literature and research gaps recognized thereon are highlighted at the end of each section/sub-section.
Findings
The paper reveals important aspects related to RMS research since its inception. It also recognizes the areas of RMS research requiring more focus. The study also highlights open issues and future directions for further research.
Practical implications
The literature in the domain of RMS has so far been narrow. This paper reviews the prominent research in this field and presents an overview of its conceptual developments and various mathematical models for the RMS design and its optimization so far developed by the researchers. Further, manufacturing advancements and future directions have also been proposed for the efficient execution of RMS paradigm in manufacturing industries.
Originality/value
The paper provides an organized listing of published research work in the field of RMS. This work will provide an insight to the researchers, practitioners and others related directly or indirectly to this field to develop and understand better strategies for supervising and controlling the smooth implementation of RMS.
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Keywords
Barry Eichengreen, Michael Haines, Matthew Jaremski and David Leblang
The 1896 presidential election between William Jennings Bryan and William McKinley has new salience in the wake of the 2016 presidential contest. We provide the first systematic…
Abstract
The 1896 presidential election between William Jennings Bryan and William McKinley has new salience in the wake of the 2016 presidential contest. We provide the first systematic analysis of presidential voting in 1896, combining county-level returns with economic, financial, and demographic data. We show that Bryan did well where interest rates were high, railroad penetration was low, and crop prices had declined. We show that further declines in crop prices or increases in interest rates would have been enough to tip the Electoral College in Bryan’s favor. But to change the outcome, the additional changes would have had to be large.
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Morteza Khojastehpour and Md Abu Saleh
Corporate social responsibility (CSR) has received considerable research attention globally over the past decade. Although a growing number of prior studies have investigated the…
Abstract
Purpose
Corporate social responsibility (CSR) has received considerable research attention globally over the past decade. Although a growing number of prior studies have investigated the various dimensions of CSR in general terms, few studies have investigated the critical role that CSR can play in the internationalization process of firms.
Design/methodology/approach
Using S&P 500 companies during 2004-2014, the authors found that the level of CSR commitment raises the level of reliability of firm and allows further international penetration. Moreover, better regulatory quality of host country is at actual support of internationalization only when considering the short term.
Findings
Better regulatory quality of host country is at actual support of internationalization only when considering the short term.
Originality/value
The authors build on internationalization theory and CSR and examine the relationship between firms’ level of internationalization and CSR commitment.
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Ling Wang, Fujun Wang, Bryan William Karney, Ahmad Malekpour and Zhengwei Wang
The velocity head is usually neglected in the energy equation for a pipeline junction when one-dimensional (1D) hydraulic transient flow is solved by method of characteristics…
Abstract
Purpose
The velocity head is usually neglected in the energy equation for a pipeline junction when one-dimensional (1D) hydraulic transient flow is solved by method of characteristics. The purpose of this paper is to investigate the effect of velocity head on filling transients in a branched pipeline by an energy equation considering velocity head.
Design/methodology/approach
An interface tracking method is used to locate the air–water interface during pipeline filling. The pressured pipe flow is solved by a method of characteristics. A discrete gas cavity model is included to permit the occurrence of column separation. A universal energy equation is built by considering the velocity head. The numerical method is provisionally verified in a series pipeline and the numerical results and experimental data accord well with each other.
Findings
The numerical results show that some differences in filling velocity and piezometric head occur in the branched pipeline. These differences arise because the velocity head in the energy equation can become an important contributor to the hydraulic response of the system. It is also confirmed that a local high point in the profile is apt to experience column separation during rapid filling. Significantly, the magnitude of overpressure and cavity volume induced by filling transients at the local high point is predicted to increase with the velocity in the pipes.
Originality/value
The velocity head in the energy equation for a pipeline junction could play an important role in the prediction of filling velocity, piezometric head and column separation phenomenon, which should be given more attention in 1D hydraulic transient analysis.
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