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The tribological behavior, i.e. friction coefficient and wear rate, and vibration characteristics of the water-lubricated bearing was investigated. The water-lubricated bearing is made of three different materials, i.e. polyether-ether-ketone (PEEK), polyimide (PI) and nitrile-butadiene rubber (NBR).

The tribological behavior was investigated experimentally on a specially designed test rig. Three vibration sensors were used to record the vibration of the bearing.

The results indicated that the variation of friction coefficient with rotation speed agrees well with the trend of Stribeck curve. The tested friction coefficient of rubber bearing is higher than that of the other two bearings whether it is in the state of mixed-lubrication or hydrodynamic lubrication, and which causing a larger wear rate in rubber bearing. The PEEK bearing exhibits the best tribological properties due to it has smaller friction coefficient and wear rate. However, it can be found that the rubber bearing gives the minimum vibration acceleration, which means that the rubber bearing has the most potential to improve the stability of water-lubricated bearing rotor system.

In this study, a group of experiment studies conducted on a specially designed test rig. The comprehensive performance, including friction coefficient, vibration acceleration and wear rate, of water-lubricated bearing with three different materials, i.e. PEEK, PI and NBR, was compared systematically. The experiment research may offer a reference for the selection of material in water-lubricated bearing in specific operating conditions.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0447/

This study aims to evaluate the tribological behavior of water-lubricated rubber bearings sliding against stainless steel under different lubricate conditions.

The water-lubricated rubber bearings under various normal loads and sliding speeds were carried out on the ring-block friction test, and the wear morphology is test conducted by using scanning electron microscope.

The results indicate that the surface of water-lubricated rubber bearings has a more alternative friction coefficient and wear rate under seawater than other lubricate conditions. The seawater not only acts as a lubricating medium but also brings microstructure while corroding the rubber interface, thereby further enhancing the lubricating effect and storing abrasive debris.

In this paper, tribological properties of the water-lubricated rubber bearing on ring-block friction test has been investigated. Water-lubricated rubber bearing was carried out on various lubricate conditions, and the friction coefficient, wear rate and worn surface were analyzed. Also, the effects of sliding speeds were investigated.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0204/

This study aims to develop a new method to treat the numerical singularity at the critical nodes of two skew coordinates, and optimize the leakage of micro herringbone grooved journal bearings (MHGJBs) with this method.

A side leakage numerical algorithm is proposed by using the skew meshes with a virtual node (SMVN) method to evaluate the effects of groove angle, bank/groove ratio, groove depth and groove number on load capacity, friction and side leakage of MHGJB.

The SMVN method is effective in treating the numerical singularity at the critical nodes of two skew coordinates. Besides, a group of optimized parameters of micro herringbone groove is obtained which can not only minimize the side leakage but also improve the load capacity and friction force.

A virtual node method was proposed, which can significantly improve the calculation accuracy in the side leakage model.

Under the sunlight of social commerce, few concepts have blossomed like value co-creation. But when blurred strategies are implemented, the opportunity to wilt a brand is high. To avoid the miscues and the controversies, an ascendant step is to engage consumers with social commerce sites. The purpose of this paper is to propose three antecedents to engage consumers with social commerce sites, namely, social support, social commerce value and social commerce information sharing, and the effect of brand engagement on the intention of brand co-creation.

This study used survey data from 234 Iranians with experience using social commerce sites. Variance-based structural equation modeling using the partial least squares path modeling approach was adopted to analyze the structural model.

The authors found that social support, social commerce value and social commerce information sharing positively foster brand engagement. The study also revealed that brand engagement is a significant predictor of brand co-creation intention.

The study is the first study that considers and explains brand engagement from social support theory, social commerce value theory and social commerce information exchange. Also, the study shows how consumers can be an integral part of a brand. Unlike other studies which were done in industrialized countries, this study was employed in Iran.

The purpose of this research is to explore the effect of goal type of user-generated content (UGC) on consumers' intention of within-domain and across-domain compensatory consumption in closed social media platforms, the mediating effect of self-threat, self-enhancement and self-protection motivation and the moderating effect of self-efficacy.

Four between-subject experiments were conducted to verify the hypotheses presented in this research. Study 1a had a sample size of 60 respondents and examined the effect of goal type of UGC on compensatory consumption. Study1b replicated the effect by using a sample size of 60 respondents. Study 2 had a sample size of 70 respondents and verified the mediating role of self-threat, self-enhancement motivation and self-protection motivation. Study 3 examined self-efficacy as a critical moderator by using a sample of 255 participants.

Study 1a and Study 1b demonstrate that UGC with an attainment goal (vs maintenance goal) is more easily produced within-domain and across-domain compensatory consumption. Study 2 verifies that the effect of goal type of UGC on within-domain compensatory consumption is serially mediated by self-threat and self-enhancement motivation, and the effect of goal type of UGC on across-domain compensatory consumption is serially mediated by self-threat and self-protection motivation. Study 3 demonstrates that self-efficacy not only moderates the effects of self-threat on within-domain or across-domain compensatory consumption respectively, but also moderates the whole mediating path structure.

This research extends the understanding of UGC and addresses the inconclusive evidence of the impact of goal type of UGC on consumer compensatory behavior in the context of closed social media platforms. The authors identify the moderating role of self-efficacy, which explains why consumers adopt different compensatory strategies.

The purpose of this paper is to improve the precision of gangue detection. In the real production environment, some gangue features are not obvious, and it is difficult to distinguish between coal and gangue. The color of the conveyor belt is similar to the gangue, the background noise also brings challenge to gangue detection. To address the above problems, we propose a feature aggregation method based on optical flow (FAOF).

An FAOF is proposed. First, to enhance the feature representation of the current frame, FAOF applies the timing information of video stream, propagates the feature information of the past few frames to the current frame by optical flow. Second, the coordinate attention (CA) module is adopted to suppress the noise impact brought by the background of convey belt. Third, the Mish activation function is used to replace rectified linear unit to improve the generalization capability of our model.

The experimental results show that the gangue detection model proposed in this paper improve 4.3 average precision compared to baseline. This model can effectively improve the accuracy of gangue detection in real production environment.

The key contributions are as follows: this study proposes an FAOF; this study adds CA module and Mish to reduce noise from the background of the conveyor belt; and this study also constructs a large gangue data set.

The purpose of the paper is to predict the erosion rate of the components of centrifugal pump under certain operating condition to identify the maximum erosion area and to discuss the factors affecting them. This helps to optimize design and estimate service life.

In the paper, the Eulerian–Lagrangian approach method coupled with the erosion model to investigate the mixed sand characteristics on erosion characteristics of centrifugal pump flow-through wall. The hydraulic performance and wear characteristics experiment of the pump is used to verify the accuracy of the numerical simulation.

The blade erosion area mainly occurs near the blade inlet and the trailing edge of the pressure surface, the main erosion area of the impeller back shroud is near the outlet of the flow passage and the main erosion area of the volute is near the tongue and the I section. With the change of the average diameter and density of sand particles, the average erosion rate on different flow-through walls is positively correlated with the average mass concentration to a certain extent. However, for different sand shape factors, there is little correlation between the average erosion rate and the average mass concentration. In addition, compared with other erosion areas, the increase of average sand particle diameter and density has the greatest impact on the total erosion rate of blade pressure surface, while the shape of sand particles has a greater impact on the total erosion rate of each flow-through wall of centrifugal pump.

In this work, according to the characteristics of the mixed distribution of different sand diameters in the Yellow River Basin, the erosion characteristics of centrifugal pumps used in the Yellow River Basin are studied. The numerical calculation method for predicting the wall erosion of centrifugal pump is established and compared with the experimental results. The results can provide reference for optimizing design and increasing service life.

Despite the various benefits of social networking services (SNSs), users have begun to experience fatigue in recent years, as evidenced by a decline in active user numbers. This relatively new phenomenon has only recently received significant managerial and academic attention. The antecedents of SNS fatigue are still unclear in the literature. The purpose of this paper is to identify the key factors causing SNS fatigue, based on a socio-technical approach.

The authors empirically tested this research model with 424 SNS users via an online survey. Structural equation modeling with partial least squares was used to analyze the data.

The results showed that the social factors of social comparison, social interaction overload, social surveillance and social information overload, and the technical factor of system complexity are significantly related to SNS fatigue.

This research benefits SNS providers by allowing them to better understand how to effectively design social networking platforms to retain and attract more users. It also benefits users by providing guidance on how to actively manage their own behavior to avoid potential negative outcomes induced by SNS usage.

This study focuses on the “dark side” of SNS from the perspective of fatigue, extending existing research on technostress. It also extends the applicability of the socio-technical approach to the phenomenon of SNS fatigue. Moreover, it enriches SNS fatigue research by addressing the importance of both social and technical factors in causing SNS fatigue.