Ping Ma, Hongli Zhang, Wenhui Fan and Cong Wang
Early fault detection of bearing plays an increasingly important role in the operation of rotating machinery. Based on the properties of early fault signal of bearing, this paper…
Abstract
Purpose
Early fault detection of bearing plays an increasingly important role in the operation of rotating machinery. Based on the properties of early fault signal of bearing, this paper aims to describe a novel hybrid early fault detection method of bearings.
Design/methodology/approach
In adaptive variational mode decomposition (AVMD), an adaptive strategy is proposed to select the optimal decomposition level K of variational mode decomposition. Then, a criterion based on envelope entropy is applied to select the optimal intrinsic mode functions (OIMF), which contains most useful fault information. Afterwards, local tangent space alignment (LTSA) is used to denoising of OIMF. The envelope spectrum of the OIMF is used to analyze the fault frequency, thereby detecting the fault. Experiments are conducted in a simulated signal and two experimental vibration signals of bearings to verify the effect of the new method.
Findings
The results show that the proposed method yields a good capability of detecting bearing fault at an early stage. The new method can extract more useful information and can reduce noise, which can provide better detection accuracy compared with the other two methods.
Originality/value
An adaptive strategy based on center frequency is proposed to select the optimal decomposition level of variational mode decomposition. Envelope entropy is used to fault feature selection. Combining the advantage of the AVMD-envelope entropy and LTSA, which suits the nature of the early fault signal. So, the proposed method has better detection accuracy, which provides a good alternative for early fault detection of bearings.
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Ann Veeck, Hongyan Yu, Hongli Zhang, Hong Zhu and Fang (Grace) Yu
The purpose of this study is to explore the association between eating patterns, social identity and the well-being of adolescents via a mixed methods study of Chinese teenagers…
Abstract
Purpose
The purpose of this study is to explore the association between eating patterns, social identity and the well-being of adolescents via a mixed methods study of Chinese teenagers. The specific research questions presented in this study are as follows: What is the relationship between social eating and well-being? How is the relationship between social eating and well-being mediated by social identity?
Design/methodology/approach
This study is based on a sequential mixed methods study, including interviews with 16 teenage–parent dyads, and a large-scale survey of over 1,000 teenagers on their eating patterns, conducted with the support of public schools. A model that tests relationships among social eating, social identity and subjective well-being is developed and tested.
Findings
The results show that dining with family members leads to improved subjective well-being for teenagers, through a partial mediator of stronger family identity. However, dining with peers is not found to influence subjective well-being.
Research limitations/implications
The privileged position of family meals demonstrated through this study may be an artifact of the location of this study in one Chinese city. Further research is needed related to the connections among social identity, objective well-being and the social patterns of teenagers’ food consumption behavior.
Practical implications
To improve the subjective well-being of teenagers, families, public policy-makers and food marketers should support food consumption patterns that promote family meals.
Originality/value
While many food-related consumer studies focus on the individual, social and environmental influences of food choices of adolescents, few studies address how eating patterns affect overall well-being. These results reinforce the importance of understanding the effect of the social context of teenagers’ eating patterns on health and well-being.
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Jun Xie, Qihai Huang, Hongli Wang and Minghao Shen
The purpose of this paper is to investigate the curvilinear relationship between perceived negative workplace gossip and target employee’s task performance, and the moderating…
Abstract
Purpose
The purpose of this paper is to investigate the curvilinear relationship between perceived negative workplace gossip and target employee’s task performance, and the moderating roles of perceived organizational support (POS).
Design/methodology/approach
Using a sample of 275 supervisor–subordinate dyads in a two-wave survey, the authors adopted a hierarchical regression analysis to test the hypotheses.
Findings
The results revealed that there is a U-shaped relationship between perceived negative workplace gossip and task performance. Moreover, POS moderated the curvilinear relationship such that the curvilinear relationship is more pronounced among those with lower POS.
Research limitations/implications
This study does not explore the mediating mechanism of how perceived negative gossip affects the target’s task performance. Moreover, as this research was conducted in a Chinese context, the question of the generalizability of the findings calls for more attention.
Practical implications
When the negative gossip is still in its early stages, managers should realize the potential threat to target employees and take measures to stop and minimize negative gossiping and rumormongering. Furthermore, managers should do their best to find the optimal levels of organizational support for target employees.
Originality/value
This study is among the first effort to understand how perceived negative gossip can influence the target employees’ performance by proposing and demonstrating a nonlinear relationship. Moreover, by illuminating how POS plays a role in the curvilinear relationship between negative gossip and task performance, the authors not only complement but also extend the literature on workplace gossip and organizational support.
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Cuicui Chen, Qian Yang, Qingan Chen, Yanhui Wang, Dong Xu, Hezong Li, Xiliang Zhang, Christopher M. Harvey and Jiwei Liu
This study aims to investigate the effects of graphite-MoS2 composite solid lubricant on the tribological properties of copper-based bearing materials under dry conditions.
Abstract
Purpose
This study aims to investigate the effects of graphite-MoS2 composite solid lubricant on the tribological properties of copper-based bearing materials under dry conditions.
Design/methodology/approach
The mixture of Graphite-MoS2 was inlaid in ZQSn6-6–3 tin bronze and ZQAl9-4 aluminum bronze matrix. These copper-embedded self-lubricating bearing materials were considered in friction pairs with 2Cr13 stainless steel, and their tribological properties were studied by using an MM200 wear test machine.
Findings
The results show that the friction coefficients and wear rates of copper-embedded self-lubricating bearing materials are lower than those of the ordinary copper-based bearing materials. The wear performance of the tin bronze inlaid self-lubricating bearing material is better than that of the aluminum bronze inlaid self-lubricating bearing material. The wear mechanism of the tin bronze bearing material is mainly adhesive wear, and that of the aluminum bronze bearing material is mainly grinding wear, oxidation wear and adhesive wear. The copper-embedded self-lubricating bearing materials had no obvious abrasion, whereas the aluminum bronze inlaid self-lubricating bearing material exhibited deep furrows and obvious abrasion under high loads.
Originality/value
These results are helpful for the application of copper-embedded self-lubricating bearing materials.
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Xiaoping Zhang, Yanhui Li, Meixiu Li, Qiuju Du, Hong Li, Yuqi Wang, Dechang Wang, Cuiping Wang, Kunyan Sui, Hongliang Li, Yanzhi Xia and Yuanhai Yu
In order to discover a new adsorbent that can be used to purify dye wastewater in the textile and apparel industry, a novel type of graphene oxide/gluten composite material using…
Abstract
Purpose
In order to discover a new adsorbent that can be used to purify dye wastewater in the textile and apparel industry, a novel type of graphene oxide/gluten composite material using an improved acid bath coagulation method was synthesized, which can remove methylene blue in an aqueous environment.
Design/methodology/approach
After experimentally compounding different ratios of graphene oxide and gluten, the graphene oxide/gluten composite material with 20% graphene oxide content and superlative adsorption effect was chosen. The synthesized material was characterized by different techniques such as FT-IR and SEM, indicating the microstructure of the material and the success of the composite. Various factors were considered, namely, the influence of temperature, dosage, pH and contact time. The isotherms, kinetics and thermodynamic parameters were successively discussed.
Findings
The qmax value of 214.29 mg/g of the material was higher compared to the general sorbent, thus, the graphene oxide/gluten composite material was a suitable sorbent for methylene blue removal. Overall, the graphene oxide/gluten composite material can be considered as an effectual and prospective adsorbent to remove methylene blue in the textile and apparel industrial effluent.
Originality/value
Graphene oxide is a potentially excellent sorbent. However, the high dispersibility of GO is detrimental to adsorption, it disperses rapidly in an aqueous solution making separation and recovery difficult. The high load capacity and recyclability of gluten as a colloid make it a suitable carrier for fixing GO. Studies on the combination of GO and GT into composite adsorption material and for the removal of dyes from dyeing wastewater have not been reported. The composite material research on GO and GT can provide new ideas for the research of these kinds of materials and contribute to its wider and convenient application in wastewater treatment.
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Jing Chen and Hongli Chen
The purpose of this research is to provide insights into the daily search strategies of users, which can inform the enhancement of search experiences across multiple applications…
Abstract
Purpose
The purpose of this research is to provide insights into the daily search strategies of users, which can inform the enhancement of search experiences across multiple applications. By understanding how users navigate and interact with different apps during their search processes, the study seeks to contribute to the design of more intuitive and user-friendly app systems.
Design/methodology/approach
This study employs a mixed-methods approach to analyze users' daily search strategies in a natural cross-app interactive environment. Data collection was conducted using the Critical Incident Technique and the Micro-Moment Time Line, involving 204 participants to capture their real-time search experiences. Open coding techniques were utilized to categorize sequential search tactics, while the PrefixSpan algorithm was applied to identify patterns in frequently applied search strategies.
Findings
The study findings unveil a comprehensive framework that includes a variety of intra-app search tactics and inter-app switching tactics. Five predominant search strategies were identified: Iterative querying, Selective results adoption, Share-related, Recommended browsing, and Organizational results strategies. These strategies reflect the nuanced ways in which users engage with apps to fulfill their information needs.
Originality/value
This research represents a pioneering effort in systematically identifying and categorizing daily search strategies within a natural cross-app interaction context. It offers original contributions to the field by combining intra-app and inter-app tactics, providing a holistic view of user behavior. The implications of these findings are significant for app developers and designers, as they can leverage this knowledge to improve app functionality and user manuals, ultimately enhancing the overall search experience for users.
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Creativity itself does not necessarily lead to idea implementation. The purpose of this paper is to deeply understand the impact of the individual culture value orientation on…
Abstract
Purpose
Creativity itself does not necessarily lead to idea implementation. The purpose of this paper is to deeply understand the impact of the individual culture value orientation on employees’ motivation on whether they want to push creative ideas into implementation.
Design/methodology/approach
In this study, drawing on socially desirable responding (SDR) theory, the author reasons that individual value on power distance and superficial harmony and that these two factors interact to influence employees transform their creativity into implementation. The author argues that prevalence of the failure where creativity cannot be transformed into implementation results from the lack of understanding for two elusive individual culture value orientations: individual superficial harmony orientations (ISHO) and individual power distance orientations (IPDO). Data from 66 middle managers and 301 members of five high-tech firms provide a considerable support for the hypothesized model.
Findings
The results showed that individuals were able to improve the possibility of putting their creative ideas into practice when they are both lower in IPDO and ISHO.
Originality/value
Such findings help the author to understand how individual cultural value orientation complements each other to generate joint impact on the relationship between their creative ideas to idea implementation.
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This paper proposes a spoke-type fractional-slot concentrated windings (FSCW) permanent magnet (PM) machine for special vehicle driving systems to obtain higher torque and power…
Abstract
Purpose
This paper proposes a spoke-type fractional-slot concentrated windings (FSCW) permanent magnet (PM) machine for special vehicle driving systems to obtain higher torque and power density, high efficiency and wide field-weakening range. To enhance the efficiencies of multi-objective optimization processes, the respond surface (RS) method and black-hole (BH) algorithm are used.
Design/methodology/approach
The spoke-type FSCW PM machine is optimized to meet the requirements of the special vehicle driving system. The combination of the RS and BH algorithm is used to obtain high torque, low torque ripple and high efficiency.
Findings
The optimal spoke-type PM machine is obtained, and it has higher torque density, lower torque ripple, cogging torque and wider magnetic field weakening range. Finally, a 15-kW prototype machine is fabricated and tested to verify the results of the optimization method and finite-element analysis.
Originality/value
This paper designs a high torque density and efficiency spoke-type FSCW PM machine, which is superior for special vehicle driving systems. Meanwhile, the RS model combined with BH algorithm is applied to the field of electrical machine multi-objective optimal design.
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Zhongchao Qiu, Ruwang Mu, Yuzi Zhang, Yanan Li, Yuntian Teng and Li Hong
This study aims to solve the problem of temperature cross sensitivity of fiber Bragg grating in structural health monitoring, proposing a novel acceleration sensor based on strain…
Abstract
Purpose
This study aims to solve the problem of temperature cross sensitivity of fiber Bragg grating in structural health monitoring, proposing a novel acceleration sensor based on strain chirp effect which is insensitive to temperature.
Design/methodology/approach
A kind of M-shaped double cantilever beam structure is developed. The fiber grating is pasted in the gradient strain region of the beam, and the chirp effect is produced under the action of non-uniform stress, and then the change of acceleration is converted into the change of reflection bandwidth to demodulate and eliminate the temperature interference. Through theoretical analysis, simulation and experimental verification with rectangular beam sensor.
Findings
The results show that the sinusoidal curvature beam sensor is insensitive to the change of temperature and is more likely to produce chirp effect. The sensitivity is about 317 pm/g, and the natural frequency is 56 Hz.
Originality/value
This paper fulfils an insensitive to temperature changes sensor which has effectively solved the temperature cross-sensitivity problem in building structure health monitoring.