Xiuying Wang, Michael Khonsari, Siyuan Li, Qingwen Dai and Xiaolei Wang
This study aims to simultaneously enhance the load-carrying capacity and control the leakage rate of mechanical seals by optimizing the texture shape.
Abstract
Purpose
This study aims to simultaneously enhance the load-carrying capacity and control the leakage rate of mechanical seals by optimizing the texture shape.
Design/methodology/approach
A multi-objective optimization approach is implemented to determine the optimal “free-form” textures and optimal circular dimples. Experiments are conducted to validate the simulation results.
Findings
The experimental coefficient of friction (COF) and leakage rate are in good agreement with the calculated results. In addition, the optimal “free-form” texture shows a lower COF and a lower leakage in most cases.
Originality/value
This work provides a method to optimize the surface texture for a better combination performance of mechanical seals.
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Keywords
Xinliang Liu, Liang Cheng, Guoning Chen, Xiaolei Wang and Jingqiu Wang
The purpose of this study is to provide a new convolutional neural network (CNN) model with multi-scale feature extractor to segment and recognize wear particles in complex…
Abstract
Purpose
The purpose of this study is to provide a new convolutional neural network (CNN) model with multi-scale feature extractor to segment and recognize wear particles in complex ferrograph images, especially fatigue and severe sliding wear particles, which are similar in morphology while different in wear mechanism.
Design/methodology/approach
A CNN model named DWear is proposed to semantically segment fatigue, severe sliding particles and four other types of particles, that is, chain, spherical, cutting and oxide particles, which unifies segmentation and recognition together. DWear is constructed using four modules, namely, encoder, densely connected atrous spatial pyramid pooling, decoder and fully connected conditional random field. Different from the architectures of ordinary semantic segmentation CNN models, a multi-scale feature extractor using cascade connections and a coprime atrous rate group is incorporated into the DWear model to obtain multi-scale receptive fields and better extract features of wear particles. Moreover, fully connected conditional random field module is adopted for post-processing to smooth coarse prediction and obtain finer results.
Findings
DWear is trained and verified on the ferrograph image data set, and experimental results show that the final Mean Pixel Accuracy is 95.6% and the Mean Intersection over Union is 92.2%, which means that the recognition and segmentation accuracy is higher than those of previous works.
Originality/value
DWear provides a promising approach for wear particle analysis and can be further developed in equipment condition monitoring applications.
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Binbin Su, Wei Huang and Xiaolei Wang
This paper aims to experimentally investigate the elastic deformation behavior of surface texture in soft contacts under lubricated condition.
Abstract
Purpose
This paper aims to experimentally investigate the elastic deformation behavior of surface texture in soft contacts under lubricated condition.
Design/methodology/approach
Dimples with two typical distribution patterns are fabricated on the contacting surface by Quasi-LIGA technique. In situ observation on the elastic deformation of contacting surface is performed through optical interferometry. Comparisons of the elastic deformation around the dimples in different distribution patterns are conducted.
Findings
The results show that the effect of dimple distribution patterns on elastic deformation becomes increasingly serious with the growth of applied load. Dimples in square distribution present a stronger interaction with each other and lead to a more alleviative deformation under heavier load condition. The action range of dimple, especially in square distribution, is seriously compressed by surrounding dimples.
Originality/value
Square distribution is preferentially suggested for surface texture with respect to minimum elastic deformation in soft contacts under elastohydrodynamic lubrication condition.
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Jiandong Lu, Xiaolei Wang, Liguo Fei, Guo Chen and Yuqiang Feng
During the coronavirus disease 2019 (COVID-19) pandemic, ubiquitous social media has become a primary channel for information dissemination, social interactions and recreational…
Abstract
Purpose
During the coronavirus disease 2019 (COVID-19) pandemic, ubiquitous social media has become a primary channel for information dissemination, social interactions and recreational activities. However, it remains unclear how social media usage influences nonpharmaceutical preventive behavior of individuals in response to the pandemic. This paper aims to explore the impacts of social media on COVID-19 preventive behaviors based on the theoretical lens of empowerment.
Design/methodology/approach
In this paper, survey data has been collected from 739 social media users in China to conduct structural equation modeling (SEM) analysis.
Findings
The results indicate that social media empowers individuals in terms of knowledge seeking, knowledge sharing, socializing and entertainment to promote preventive behaviors at the individual level by increasing each person's perception of collective efficacy and social cohesion. Meanwhile, social cohesion negatively impacts the relationship between collective efficacy and individual preventive behavior.
Originality/value
This study provides insights regarding the role of social media in crisis response and examines the role of collective beliefs in the influencing mechanism of social media. The results presented herein can be used to guide government agencies seeking to control the COVID-19 pandemic.
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Jiabao Pan, Huaibiao Wu, Ao Wang, Qingwen Dai and Xiaolei Wang
This paper aims to investigate the influence of high-temperature thermal action on grease performance from the angle of film-forming performance.
Abstract
Purpose
This paper aims to investigate the influence of high-temperature thermal action on grease performance from the angle of film-forming performance.
Design/methodology/approach
A static thermal aging method was used to prepare high-temperature thermal grease samples after high-temperature thermal action. On the basis of optical interference technology, the film-forming characteristics of fresh grease samples and the grease samples after high-temperature thermal action under variable speed and fixed speed conditions were explored.
Findings
The decrease in the structural entanglement performance of the grease after short-term high-temperature thermal action makes its film-forming performance better. The mechanism is that the lubricating grease soap fiber entanglement is reduced. Although the continuous high-temperature thermal action can make the grease film-forming performance better, its mechanism is that the soap fiber structure caused by high-temperature thermal action is damaged and is easy to be cut off under the action of shear.
Originality/value
The effect of structural system change on its film formation performance was discussed in combination with the change in grease structure characteristics, and the mechanism of action was revealed.
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Keywords
Dang Luo, Muffarah Ambreen, Assad Latif and Xiaolei Wang
Electricity plays an important role in the economic condition of any country. Nowadays, Pakistan is badly affected by shortage of electricity, which directly affected the economic…
Abstract
Purpose
Electricity plays an important role in the economic condition of any country. Nowadays, Pakistan is badly affected by shortage of electricity, which directly affected the economic growth of state. The purpose of this study is to propose an improved grey model DGPM(1,1,N) to forecast Pakistan's production of electricity, installed capacity and consumption.
Design/methodology/approach
To significantly simulate and predict accuracy, the discrete grey polynomial model DGPM(1,1,N) is improved with new information priority accumulation. The particle swarm optimization (PSO) algorithm is used for parameter optimization. The value of parameter is adjusted into improved grey model. By adjusting the parameter value in the model, the accuracy of prediction is enhanced.
Findings
The installed capacity of electricity needs more attention to improvement through implementation of effective polices, resolving major issues and funding scheme to fulfill the electricity demand of country. And improved DGPM(1,1,N) has better accuracy than original DGPM(1,1,N), DGM(1,1), nongrey models, linear regression and Holt–Winters methods.
Practical implications
This paper provides a practical and efficient improved grey method to predict the electricity production, consumption and installed capacity in Pakistan. This research and suggestion will help Pakistani government to formulate better policies to decrease the consumption of electricity and increase the installed capacity of electricity.
Originality/value
This paper not only improves the grey model with accumulation generation operator but also forecasts Pakistan's electricity production, installed capacity and consumption. It is a new idea to predict the installed capacity of electricity and the findings provide suggestions for the government to make policies.
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Keywords
Mancheng Xu, Guanghu Jin, Qingwen Dai, Wei Huang and Xiaolei Wang
This paper aims to prevent oil starvation and improve the service life of the rolling bearings.
Abstract
Purpose
This paper aims to prevent oil starvation and improve the service life of the rolling bearings.
Design/methodology/approach
A thrust ball bearing with magnetic circuit structure is proposed for ferrofluid lubrication. With the aid of magnetic field, ferrofluid can be maintained in the contact area of rolling bodies to delay lubricant loss. Experiments are performed to ensure the validity of the designed bearing.
Findings
Compared with conventional lubricant, service life of the ferrofluid lubricated bearing can be prolonged under magnetic field. In addition, with a proper magnetic field distribution, lubricant starvation may be limited under the conditions of present experiments.
Originality/value
This work provides a method to control the starved lubrication of rolling bearings with restricted lubricant supply.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2020-0132/
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Qianqian Li, Bo Zhang, Tao Yang, Qingwen Dai, Wei Huang and Xiaolei Wang
The purpose of this paper is to artificially construct a functional surface with self-propulsion flow characteristics for the directional transportation of propellant in surface…
Abstract
Purpose
The purpose of this paper is to artificially construct a functional surface with self-propulsion flow characteristics for the directional transportation of propellant in surface tension tanks.
Design/methodology/approach
In this study, a method to enhance the propulsion efficiency by using functional surfaces of self-propulsion performance was proposed. Superhydrophilic wedged-groove with the superhydrophobic background was fabricated and the self-propulsion capacity was verified.
Findings
It is found that the self-propulsion capacity is related to the divergence angle of the wedged-groove in the hydrophilic area, and the velocity of the droplets on the deflector plate is the largest with the divergence angle of 4°; the temperature gradient field formed by the condensing device at the nozzle can accelerate the droplet outflow from the tank.
Originality/value
Realization of this idea provides an accurate control strategy for the complex flow process of propellant in plate surface tension tanks, which could enhance the efficiency of the tension tank significantly.
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Keywords
Xiaolei Wang, Xiaonan Zhang, Sanyuan Shi and Libo Liu
Combining with an instance of rectification and reinforcement of a brick-concrete structure house in the Yunnan province, a comprehensive landing method was proposed. The building…
Abstract
Combining with an instance of rectification and reinforcement of a brick-concrete structure house in the Yunnan province, a comprehensive landing method was proposed. The building was reinforced, for the existing problems, on the basis of the analysis of the building tilt reasons. In order to ensure building safety in the process of rectifying inclination, the anchor static pile was used. The result showed that the inclination rate of the building returned to 3 % from 14.4 %, which proves the effectiveness of the proposed method.
Details
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Ying Wang, Hanhui Hu and Xiaolei Yang
Government R&D subsidies is a major practice to respond to market failures in most countries. The purpose of this study is to examine the effect of the government subsidies on…
Abstract
Purpose
Government R&D subsidies is a major practice to respond to market failures in most countries. The purpose of this study is to examine the effect of the government subsidies on China’s regional innovation output empirically under the regional innovation framework, for the unique regional innovation system and strong national influence of state during the period of transformation.
Design/methodology/approach
Based on the construction of regional innovation framework, this study empirically examined the effect of Chinese Government R&D subsidies on regional innovation during the economic transition period using the Bayesian model averaging method and carried out the robustness test under different priori assumptions.
Findings
The empirical results showed that R&D capital and human investment has a very significant impact on promoting the regional innovation output of China’s high-tech industries. Meanwhile, the Chinese Government's R&D subsidies failed, thus the goal of improving regional innovation output has not been achieved. In reverse, the effects of regional economic development level and the financial environment on regional innovation are negative but the explanatory power is minimal. Additionally, opening-up has greatly promoted regional innovation output.
Originality/value
The empirical findings provide scientific policy decision-making and management implications for government and firm, respectively, and its experience is a very important reference for other emerging economies. Additionally, China serves as an interesting case to examine whether government R&D subsidy is effective in an immature market.