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An investigation was conducted into the impact of various process parameters on the surface and subsurface quality of glass-ceramic materials, as well as the mechanism of material removal and crack formation, through the use of ultrasonic-assisted grinding.

A mathematical model of crack propagation in ultrasonic-assisted grinding was established, and the mechanism of crack formation was described through the model. A series of simulations and experiments were conducted to investigate the impact of process parameters on crack depth, surface roughness, and surface topography during ultrasonic-assisted surface and axial grinding. Additionally, the mechanism of crack formation was explored.

During ultrasonic-assisted grinding, the average grinding forces are between 0.4–1.0 N, which is much smaller than that of ordinary grinding (1.0–3.5 N). In surface grinding, the maximum surface stresses between the workpiece and the tool gradually decrease with the tool speed. The surface stresses of the workpiece increase with the grinding depth, and the depth of subsurface cracks increases with the grinding depth. With the increase of the axial grinding speed, the subsurface damage depth increases. The roughness increases from 0.780um/1.433um.

A mathematical model of crack propagation in ultrasonic-assisted grinding was established, and the mechanism of crack formation was described through the model. The deformation involved in the grinding process is large, and the FEM-SPH modeling method is used to solve the problem that the results of the traditional finite element method are not convergent and the calculation efficiency is low.

This paper aims to examine three of the major issues relating to the welfare of seafarers, including wages, social security benefits and onboard and ashore welfare facilities and services. It is impossible to research all countries here, so this paper selects Greece – which is one of today’s primary shipping countries as for shipowning, as well as for global supply and demand for seafarers – to conduct an empirical case study.

Based on the existing knowledge and scholarship, and primary data collected in several phases of fieldwork, this paper intends to critically examine three major issues relating to the welfare for Greek seafarers, namely, wages, social security benefits and onboard and ashore welfare facilities and services.

This paper finds that they face poor labour conditions, which are getting worse due to the depressed world and Greek economies and intense financial pressures on shipping companies. The entry into force of the Maritime Labour Convention 2006 has a significant impact on the world maritime industry.

This paper critically examines the three major issues relating to the welfare of Greek seafarers.

Such issues, which Greece is facing are also common in other countries, so the findings and suggestions revealed from this paper are of importance for the global shipping industry and other states.

In the pursuit of competitive advantage, an increasing number of firms are adopting open innovation (OI) strategies. However, previous studies have often overlooked the role of strategic human resource management (SHRM) in promoting OI. This study aims to fill this gap by examining how SHRM impacts OI through the mediating factors of intellectual capital (IC) and supply chain integration (SCI). This research sheds light on the critical interplay between SHRM, IC and SCI in driving OI success. The findings underscore the importance of adopting a comprehensive and integrated approach to OI that encompasses both resources and dynamic capabilities.

By integrating resource-based view with the dynamic capability perspective, the hypotheses were tested with a survey sample of 136 Chinese manufacture firms using hierarchical regression and bootstrap method.

The results show that SHRM has a positive effect on OI, and both IC and SCI are partial mediators of the relationship between SHRM and OI. In addition, the chain mediation effect of “SHRM-IC-SCI-OI” has further been verified.

This study uncovers the “black box” between SHRM and OI, and responds to the call for strengthening research on the relationship between SHRM and OI. The study indicates that firms should implement HR practices, including extensive training, team reward and internal promotion to promote the implementation of OI strategy.

The purpose of this paper is to study the variations of composition and properties of the passive film on 316 L stainless steel surface in 80°C, 0.5 mol L-1 H2SO4 + 2 mg L-1 NaF solution, is helpful to understand the mechanisms of corrosion resistancethe of plated Pd on 316 L ss.

The variations of composition and properties of the passive film on 316 L stainless steel surface in 80°C, 0.5 mol L-1 H2SO4 + 2 mg L-1 NaF solution after connected to Pd electrode were studied with methods of potential monitor, X-ray photoelectron spectroscopy analysis and electrochemical impedance spectrum (EIS) measurement.

By connecting to a Pd electrode, the potential of the SS sample increased from the active region to the passive region. By connecting to the Pd electrode, the contents of Cr, Cr(OH)3 and Fe3O4 in passive film increased obviously. With increased Pd/SS area ratio, the Cr(OH)3 content in passive film increased but the Fe3O4 content changed little. The results show that after connecting to Pd the corrosion resistance of the passive film on 316 L stainless steel increases obviously, which may be attributed to the more compact passive film because of higher Cr, Cr(OH)3 and Fe3O4 contents and less point defects in the film.

The effects and mechanism of Pd on passivation of SS was studied.

This study explores the effects of different types of technology lock-in on enterprise innovation performance. On this basis, the authors aim to provide technological innovation suggestions for the long-term development of Chinese enterprises.

A total of 211 high-tech enterprises in China were taken as the research sample. Data were collected through questionnaire surveys and secondhand data. Linear and nonlinear regression models were used to test the hypotheses.

Different types of technology lock-in had different effects on enterprise innovation performance. Initiative lock-in and passive lock-in showed an inverted U-shaped relationship with innovation performance. Economies of scale were positively correlated with innovation performance, while self-lock-in was negatively correlated with it.

This research can help enterprises reconceptualize technology lock-in. It can also help enterprises in different stages of development carry out targeted technological innovation and management strategies.

This research enriches our understanding of technology lock-in. By breaking with previous conceptualizations of a simple linear relationship between technology lock-in and innovation performance, this study proposes and confirms different technology lock-in has different relationships with enterprise innovation performance. This study is important for enterprises to reassess their technology lock-in state and carry out targeted technological innovation strategies. This research enriches the theory of path dependence and its combination with other theories. And this study also reveals the current research on technology lock-in is insufficient.

Due to the structural layout, mining process, and working environment, curved chains such as horizontal and vertical bends inevitably exist in the armoured face conveyor (AFC). With the increasing power, conveying capacity, and distance of the AFC, the dynamic influence of these curved chains should be highly emphasized. This paper establishes a dynamic model of the AFC by multi-body system theory and finite segment method, in which the curved chains can be fully considered.

The scraper chains are firstly grouped into the straight, horizontal bend, vertical convex and concave bend sections. Each bend section running in a circle is simplified as an ideal arc. Through solving its differential equilibrium equation and using Newton's second law, its running resistance is derived. Then the grouped chains are discretized into finite control elements according to the Kelvin model, and the governing equation of each control element is established. The dynamic model of the AFC is obtained by assembling these equations, and the corresponding simulation model is developed by using MATLAB/Simulink.

Case studies with real scenarios are provided, and simulations are carried out. The results show that the running resistance contributed by the curved chains is larger than the traditional empirical value.

The work in this paper helps the dynamic performance design of AFC, with a deep understanding of the curved chains.

To further understand the granular flow lubrication mechanism in metal contact pairs, the effect of sliding-rolling ratio on the force chain properties was investigated.

The parallel inter-plate model of the granular flow lubrication was established with discrete element method. Then, the correlation law between sliding-rolling ratio and force chain evolution properties was calculated and analyzed with PFC2D software platform.

Numerical calculation results show that the dynamic fluctuation property of force chain is existed, and the shock frequency of it is increased with the increase of sliding-rolling ratio. The same evolution law is also occurred for the bearing rate of strong force chain in the initial expansion and final compression phases, and the opposite phenomena is obtained for the overall expansion phase. Moreover, the directivity of strong force chain is changed by the sliding-rolling ratio. With the increase of sliding-rolling ratio, the directivity of strong force chain is first tended to y-axis, and then inclined to the x-axis in the whole phases. The basic reason is that a clamping up and downward movement impact for the neighbor particles are the essence of the above phenomenon.

The main contribution of this work is to lay a theory foundation of interfacial lubrication mechanism with granular flow.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0133/

The purpose of this paper is to identify electronic word-of-mouth (eWOM) customers from customer reviews. Thus, firms can precisely leverage eWOM customers to increase their product sales.

This research proposed a framework to analyze the content of consumer-generated product reviews. Specific algorithms were used to identify potential eWOM reviewers, and then an evaluation method was used to validate the relationship between product sales and the eWOM reviewers identified by the authors’ proposed method.

The results corroborate that online product reviews that are made by the eWOM customers identified by the authors’ proposed method are more related to product sales than customer reviews that are made by non-eWOM customers and that the predictive power of the reviews generated by eWOM customers are significantly higher than the reviews generated by non-eWOM customers.

The proposed method is useful in the data set, which is based on one type of products. However, for other products, the validity must be tested. Previous eWOM customers may have no significant influence on product sales in the future. Therefore, the proposed method should be tested in the new market environment.

By combining the method with the previous customer segmentation method, a new framework of customer segmentation is proposed to help firms understand customers’ value specifically.

This study is the first to identify eWOM customers from online reviews and to evaluate the relationship between reviewers and product sales.

Based on the prediction of the consumption of medical materials, the purpose of this paper is to study the applicability of the grey model method to the field and its predicted accuracy.

The ABC classification method is used to classify medical consumables and select the analysis objects. The GM (1,1) model predicts the annual consumption of medical materials. The GM (1,1) modeling of the consumption of the selected medical materials in 2006~2017 was carried out by using the metabolite sequence and the sequence topology subsequence, respectively. The average rolling error and the average rolling accuracy are calculated to evaluate the prediction accuracy of the model.

The ABC classification results show that Class A projects, which account for only 9.79 percent of the total inventory items, occupy most of the inventory funds. Eight varieties with varying purchases and usages and complete historical data were selected for further analysis. The subsequence GM(1,1) model group constructed by two different methods predicts and scans the annual consumption of eight kinds of medical materials, and the rolling precision can reach more than 90 percent.

The metabolic GM (1,1) model is an ideal predictive model that can meet the requirements for a short-term prediction of medical material consumption (Zhang et al., 2014). The GM (1,1) model is more suitable for a short-term prediction of medical material consumption with less data modeling.

The oil film thickness provides a key performance indicator of a ball bearing lubrication condition. This paper aims to propose an approach to calculate and measure the oil film thickness of the bearing.

On a specially designed test rig, measurement of the capacitance is used to monitor the oil film thickness of ball bearing. A corrected film thickness formula taking account of the influences of non-Newtonian shear thinning and thermal is introduced to predict the oil film thickness of ball bearing. And then the film thickness distribution and the corresponding capacitances are calculated.

Measurement and calculation of oil film thickness in a ball bearing are carried out under various rotating speeds and external loads. By comparing the calculated capacitances with measured results, it can be concluded that the calculated results obtained by the amended film thickness formula are much closer to the test findings than the classical computed values according to Hamrock–Dowson.

A new corrected film thickness formula is introduced in predicting oil film thickness of ball bearing and verified by the series of experiments according to capacitance method.