Jianmei Wang, Zhixiong Li, Sadoughi Mohammadkazem, Min Cai, Jianfeng Kang and Yanan Zhang
The stability characteristics of an oil film directly influence the safety and service life of mill oil-film bearings. However, very limited work has been done to address the…
Abstract
Purpose
The stability characteristics of an oil film directly influence the safety and service life of mill oil-film bearings. However, very limited work has been done to address the stability characteristics of mill oil-film bearings. To this end, this paper aims to investigate the stability characteristics of mill oil-film bearings through theoretical and experimental analysis.
Design/methodology/approach
For the first time, a special designed experiment platform was developed to investigate the stability characteristics of mill oil-film bearings. In addition, a theoretical model of lubricating film of the tested bearings was established to analyze the oil-film stability. The theoretical results were compared with the experimental results.
Findings
The comparison results demonstrate that the critical influential factors on the bearing stability were the eccentricity ratio and the ratio of bearing length to diameter. The mill bearing was likely to be unstable under a small load and at a high rotational speed.
Practical implications
The paper includes implications for suitable operation conditions in practical use of mill oil-film bearings.
Originality/value
This paper fulfills an identified need to investigate oil-film stability of mill bearings for practical applications.
Details
Keywords
Yan Wang, Shibin Wei, Fei Yang, Jiyou Fei and Jianfeng Guo
This study aims to analyze the development direction of track geometry inspection equipment for high-speed comprehensive inspection train in China.
Abstract
Purpose
This study aims to analyze the development direction of track geometry inspection equipment for high-speed comprehensive inspection train in China.
Design/methodology/approach
The development of track geometry inspection equipment for high-speed comprehensive inspection train in China in the past 20 years can be divided into 3 stages. Track geometry inspection equipment 1.0 is the stage of analog signal. At the stage 1.0, the first priority is to meet the China's railways basic needs of pre-operation joint debugging, safety assessment and daily dynamic inspection, maintenance and repair after operation. Track geometry inspection equipment 2.0 is the stage of digital signal. At the stage 2.0, it is important to improve stability and reliability of track geometry inspection equipment by upgrading the hardware sensors and improving software architecture. Track geometry inspection equipment 3.0 is the stage of lightweight. At the stage 3.0, miniaturization, low power consumption, self-running and green economy are co-developing on demand.
Findings
The ability of track geometry inspection equipment for high-speed comprehensive inspection train will be expanded. The dynamic inspection of track stiffness changes will be studied under loaded and unloaded conditions in response to the track local settlement, track plate detachment and cushion plate failure. The dynamic measurement method of rail surface slope and vertical curve radius will be proposed, to reveal the changes in railway profile parameters of high-speed railways and the relationship between railway profile, track irregularity and subsidence of subgrade and bridges. The 200 m cut-off wavelength of track regularity will be researched to adapt to the operating speed of 400 km/h.
Originality/value
The research can provide new connotations and requirements of track geometry inspection equipment for high-speed comprehensive inspection train in the new railway stage.
Details
Keywords
Umar Farooq Sahibzada, Jianfeng Cai, Khawaja Fawad Latif and Hassam Farooq Sahibzada
Drawing on the knowledge-based view, the purpose of this paper is to investigate the interrelationship between Knowledge Management (KM) processes, Knowledge Worker Satisfaction…
Abstract
Purpose
Drawing on the knowledge-based view, the purpose of this paper is to investigate the interrelationship between Knowledge Management (KM) processes, Knowledge Worker Satisfaction (KWS) and Organizational Performance (OP). Additionally, the study further seeks to identify the combinations of KM processes and KWS dimensions that can lead to enhanced OP.
Design/methodology/approach
Data were collected from 248 academics and administration employees of Higher Education Institutions (HEIs). The relationships were tested using SmartPLS 3.2.7. The study also employed fuzzy set Qualitative Comparative Analysis (fsQCA) for examining configurational paths.
Findings
The results of the study revealed that KM processes significantly affect KWS and KWS enhances OP in HEIs. Based on fsQCA, the results revealed multiple configurational paths to improved OP.
Originality/value
There is significant lack of research that ascertains the inter-relationship between KM processes, KWS, and OP. This is one of the initial studies that examines the relationship of KM processes, KWS, and OP in HEI’s. From a methodological perspective, the study contributes by combining symmetric and asymmetric statistical tools in KM literature. fsQCA helps to understand the interactions that might not be immediately obvious through traditional symmetric methods.
Details
Keywords
Umar Farooq Sahibzada, Cai Jianfeng, Khawaja Fawad Latif and Hassam Farooq Sahibzada
Constructed upon knowledge-based view, the study examines the influence of internal marketing on knowledge management processes and the indirect association of knowledge…
Abstract
Purpose
Constructed upon knowledge-based view, the study examines the influence of internal marketing on knowledge management processes and the indirect association of knowledge management processes with organizational performance through mediating role of knowledge worker satisfaction.
Design/methodology/approach
This study used a sample frame of 536 academic and administrative employees from higher education institutions in China; structural equation modeling was performed using Smart PLS 3.2.8.
Findings
The outcome reveals that internal marketing has a significant impact on knowledge management processes. The results revealed a direct insignificant impact of knowledge management processes on organizational performance; the study found full mediation of knowledge worker satisfaction on the linkage between knowledge management processes and organizational performance.
Practical implications
Outcomes of this research strengthen the universities’ experience of knowledge management and recommend how academics and administrators of higher education institute can value knowledge worker satisfaction, which in turn improves organizational performance.
Originality/value
Although, there is an increased significance of knowledge management in higher education institutions, there is a lack of research that examines the enabling factors and outcomes of knowledge management practices. The present study is one of the first studies to ascertain the relationship of internal marketing, knowledge management processes, knowledge worker satisfaction and organizational performance. This is one of the initial research studies that not only empirically examines the interrelationships among these variables but also enlightens insights into the current literature by instantaneous investigation of the mediating role of knowledge worker satisfaction.
Details
Keywords
Hassam Farooq Sahibzada, Cai Jianfeng, Umar Farooq Sahibzada, Roshi Khalid and Gul Afshan
The study explores the impact of knowledge-oriented leadership (KOL) on knowledge management (KM) processes and the indirect relationship of KM processes with organizational…
Abstract
Purpose
The study explores the impact of knowledge-oriented leadership (KOL) on knowledge management (KM) processes and the indirect relationship of KM processes with organizational performance (OP) via mediating the role of creative organizational learning (COL) in cross-cultural settings.
Design/methodology/approach
This research used a survey structure of 784 faculty and admin personnel from higher education institutions in China and Pakistan. Smart-PLS, 3.2.9 was used to perform analysis.
Findings
The result shows a significant positive influence of KOL on KM processes and KM processes on OP via the partial mediating effect of COL in China, Pakistan and the overall sample. The multi-group analysis confirmed the substantial differential effect of KOL on KM processes.
Practical implications
Outcomes of this research affirm KM's university practice and recommend how higher education academics and administrators prioritize KOL, KM processes and COL while strengthening OP in a culturally different environment.
Originality/value
The current research is among the initial experiments to determine KOL, KM processes, COL and organizational (University) performance relationships in a culturally different environment. The study is among the initials that just not empirically explore the associations between the factors but sheds light on existing literature by immediately exploring COL's mediating position in China and Pakistan's HEIs.
Details
Keywords
Hina Munir, Cai Jianfeng and Sidra Ramzan
The purpose of this paper is to extend the existing literature on entrepreneurial intentions (EIs) by employing the integrated model of personality traits and the theory of…
Abstract
Purpose
The purpose of this paper is to extend the existing literature on entrepreneurial intentions (EIs) by employing the integrated model of personality traits and the theory of planned behavior (TPB). It further examines the mediating role of TPB’s dimensions between personality traits and EIs of final-year university students in two diverse economies: China and Pakistan.
Design/methodology/approach
The paper uses a survey method for data collection, administered both in electronic and paper form. The authors use structural equation modeling and the partial least square (PLS) method on a sample of 1,016 students and present PLS path modeling, mediation analysis and multigroup analysis.
Findings
Results reveal several differences regarding personality traits and TPB on EIs across the two countries. The impact of TPB was positive and significant in both countries; however, TPB demonstrated more explaining power in China’s student sample. Using three personality traits (risk-taking propensity, proactive personality and internal locus of control) as antecedents to TPB, the results reveal a stronger influence of personality traits among Chinese students. The mediation of three dimensions of TPB also revealed differences between country samples.
Originality/value
This is the first study of its kind to compare and contrast the differences between EIs in terms of personality and the determinants of planned behavior among university students in two diverse economies. The integrated model is original, supports both TPB and personality factors and provides a valuable perspective through its findings on two culturally diverse Asian countries. By applying the model in two different cultures, this study distinguishes the results for the two economies from those conducted in other economies.
Details
Keywords
Penggao Zhang, Boqin Gu, Jianfeng Zhou and Long Wei
The purpose of this study is to investigate the heat transfer characteristics in a spiral groove mechanical seal lubricated by magnetic fluid.
Abstract
Purpose
The purpose of this study is to investigate the heat transfer characteristics in a spiral groove mechanical seal lubricated by magnetic fluid.
Design/methodology/approach
The viscosity relationship of magnetic fluid in external electromagnetic field was deduced. The temperature distribution of sealing ring was calculated by the method of separation variables.
Findings
It has been found that the rotating ring absorbs most friction heat. The temperatures on the end faces of rotating ring and stationary ring decrease from inner radius to outer radius, the temperature of magnetic fluid film decreases from rotating ring to stationary ring and the highest temperature of the sealing system is at the junction of the inner radius and the end face of rotating ring.
Originality/value
Selecting the sealing rings with higher thermal conductivity and reducing the volume fraction of solid particles in magnetic fluid can reduce the temperature of sealing system effectively.
Details
Keywords
Penggao Zhang, Boqin Gu, Jianfeng Zhou and Long Wei
The purpose of this study is to investigate the hydrodynamic lubrication characteristics of ferrofluid film for spiral groove mechanical seal in external electromagnetic field and…
Abstract
Purpose
The purpose of this study is to investigate the hydrodynamic lubrication characteristics of ferrofluid film for spiral groove mechanical seal in external electromagnetic field and to analyze the effects of the volume fraction of ferrofluid, parameters of the electromagnetic field, operating parameters and geometrical parameters of mechanical seal on the characteristics of ferrofluid film.
Design/methodology/approach
The relationship between the ferrofluid viscosity and the intensity of external electromagnetic field was established. Based on the Muijderman narrow groove theory, the pressure distribution was calculated with the trial method by trapezoid formula.
Findings
It was found that pressure, average viscosity, average density and opening force of ferrofluid between end faces increase with the increase in intensity of current, volume fraction of ferrofluid, rotating speed, pressure differential and spiral angle; decrease with the increase in temperature; and increase at first and then decrease with the increase in the ratio of groove width to weir and the groove length. All of them reach the maximum value when the ratio of width of groove to weir is 0.7 and the ratio of groove length is 0.6. Leakage of ferrofluid increases with an increase in intensity of current, volume fraction of ferrofluid, rotating speed, pressure differential, spiral angle and ratio of groove length; decreases with an increase in temperature; and increases at first and then decreases with the increase in the ratio of groove width to weir. The tendencies of characteristics of silicone oil are consistent with those of ferrofluid, and the characteristics of silicone oil are smaller than those of ferrofluid under the same condition.
Originality/value
The volume fraction of ferrofluid, rotating speed, spiral angle, ratio of groove width to weir, groove length and temperature have a significant influence on the characteristics of ferrofluid film; however, intensity of current and the pressure differential have slight influence on the characteristics of ferrofluid film. An analytical method for analyzing hydrodynamic lubrication characteristics of ferrofluid film in a spiral groove mechanical seal was proposed based on the Muijderman narrow groove theory.
Details
Keywords
Zhe Wang, Xisheng Li, Xiaojuan Zhang, Yanru Bai and Chengcai Zheng
How to model blind image deblurring that arises when a camera undergoes ego-motion while observing a static and close scene. In particular, this paper aims to detail how the…
Abstract
Purpose
How to model blind image deblurring that arises when a camera undergoes ego-motion while observing a static and close scene. In particular, this paper aims to detail how the blurry image can be restored under a sequence of the linear model of the point spread function (PSF) that are derived from the 6-degree of freedom (DOF) camera’s accurate path during the long exposure time.
Design/methodology/approach
There are two existing techniques, namely, an estimation of the PSF and a blind image deconvolution. Based on online and short-period inertial measurement unit (IMU) self-calibration, this motion path has discretized a sequence of the uniform speed of 3-DOF rectilinear motion, which unites with a 3-DOF rotational motion to form a discrete 6-DOF camera’s path. These PSFs are evaluated through the discrete path, then combine with a blurry image to restoration through deconvolution.
Findings
This paper describes to build a hardware attachment, which is composed of a consumer camera, an inexpensive IMU and a 3-DOF motion mechanism to the best of the knowledge, together with experimental results demonstrating its overall effectiveness.
Originality/value
First, the paper proposes that a high-precision 6-DOF motion platform periodically adjusts the speed of a three-axis rotational motion and a three-axis rectilinear motion in a short time to compensate the bias of the gyroscope and the accelerometer. Second, this paper establishes a model of 6-DOF motion and emphasizes on rotational motion, translational motion and scene depth motion. Third, this paper addresses a novel model of the discrete path that the motion during long exposure time is discretized at a uniform speed, then to estimate a sequence of PSFs.
Details
Keywords
Feng Zhou, Zixuan Wang and Yuxiang Zhao
The purpose of this paper is to study the pipe-type electromagnetic induction heating device under power frequency condition.
Abstract
Purpose
The purpose of this paper is to study the pipe-type electromagnetic induction heating device under power frequency condition.
Design/methodology/approach
To reduce eddy current loss and improve heating efficiency, the structure of a pipe-type power-frequency electromagnetic heating device was optimized. Based on the maximum load flow formula, a parallel excitation winding structure is designed, and the distribution of electromagnetic field under four different powers is analyzed by simulation. Four heating modes were proposed according to the structure of diversion ring, inner wall and outer wall. Two heating modes with better heating effect were obtained by comprehensively considering the factors such as magnetic field distribution, thermal power and energy consumption.
Findings
The double-wall structure of the pipe-type electromagnetic heating device can make the heat source distribution more uniform, and the use of power-frequency power supply can increase security, the installation of diversion ring can make the heating more sufficient and the heating efficiency of the two heating methods selected according to the structural performance is more than 90%.
Originality/value
In view of the medium or high frequency of pipe-type electromagnetic heating device, it is necessary to configure high power electronic frequency conversion drive system, and eddy current can only be produced on the tube wall, resulting in uneven distribution of heat sources. A pipe-type power-frequency electromagnetic heating device with double-wall structure was proposed.