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Article
Publication date: 17 April 2023

Yukun Wei, Leyang Dai, YanFei Fang, Chen Xing Sheng and Xiang Rao

The purpose of this paper is to enhance the characteristics of TiO2 nanoparticles (NPs). Because these NPs stick together easily and are difficult to distribute evenly, they…

101

Abstract

Purpose

The purpose of this paper is to enhance the characteristics of TiO2 nanoparticles (NPs). Because these NPs stick together easily and are difficult to distribute evenly, they cannot be used extensively in lubricating oils. Altering TiO2 was recommended as an alternate way for making NPs simpler to disperse.

Design/methodology/approach

Through dielectric barrier discharge plasma (DBDP)-assisted ball mill diagnostics and modeling of molecular dynamics, TiO2@PEG-400 NPs were produced using the DBDP-assisted ball mill. The NPs’ microstructure was examined using FESEM, TEM, XRD, FT-IR and TG-DSC. Using the CFT-1 reciprocating friction tester, the tribological properties of TiO2@PEG-400 NPs as base oil additives were studied. EDS and XPS were used to examine the surface wear of the friction pair.

Findings

Tribological properties of the modified NPs are vastly superior to those of the original NPs, and the lipophilicity value of TiO2 NPs was improved by 200%. It was determined through tribological testing that TiO2@PEG-400’s exceptional performance might be attributable to a chemical reaction film made up of TiO2, Fe2O3, iron oxide and other organic chemicals.

Originality/value

This work describes an approach for preventing the aggregation of TiO2 NPs by coating their surface with PEG-400. In addition, the prepared NPs can enhance the tribological performance of lubricating oil. This low-cost, high-performance lubricant additive has tremendous promise for usage in marine engines to minimize operating costs while preserving navigational safety.

Details

Industrial Lubrication and Tribology, vol. 75 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Available. Open Access. Open Access
Article
Publication date: 20 August 2024

Liang Chen, Liyi Xiong, Fang Zhao, Yanfei Ju and An Jin

The safe operation of the metro power transformer directly relates to the safety and efficiency of the entire metro system. Through voiceprint technology, the sounds emitted by…

149

Abstract

Purpose

The safe operation of the metro power transformer directly relates to the safety and efficiency of the entire metro system. Through voiceprint technology, the sounds emitted by the transformer can be monitored in real-time, thereby achieving real-time monitoring of the transformer’s operational status. However, the environment surrounding power transformers is filled with various interfering sounds that intertwine with both the normal operational voiceprints and faulty voiceprints of the transformer, severely impacting the accuracy and reliability of voiceprint identification. Therefore, effective preprocessing steps are required to identify and separate the sound signals of transformer operation, which is a prerequisite for subsequent analysis.

Design/methodology/approach

This paper proposes an Adaptive Threshold Repeating Pattern Extraction Technique (REPET) algorithm to separate and denoise the transformer operation sound signals. By analyzing the Short-Time Fourier Transform (STFT) amplitude spectrum, the algorithm identifies and utilizes the repeating periodic structures within the signal to automatically adjust the threshold, effectively distinguishing and extracting stable background signals from transient foreground events. The REPET algorithm first calculates the autocorrelation matrix of the signal to determine the repeating period, then constructs a repeating segment model. Through comparison with the amplitude spectrum of the original signal, repeating patterns are extracted and a soft time-frequency mask is generated.

Findings

After adaptive thresholding processing, the target signal is separated. Experiments conducted on mixed sounds to separate background sounds from foreground sounds using this algorithm and comparing the results with those obtained using the FastICA algorithm demonstrate that the Adaptive Threshold REPET method achieves good separation effects.

Originality/value

A REPET method with adaptive threshold is proposed, which adopts the dynamic threshold adjustment mechanism, adaptively calculates the threshold for blind source separation and improves the adaptability and robustness of the algorithm to the statistical characteristics of the signal. It also lays the foundation for transformer fault detection based on acoustic fingerprinting.

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Article
Publication date: 1 April 2022

Yanfei Wang, Caiping Wu, Xiaoxia Tian and Yu Zhu

Based on the micro role transition theory (MRTT), the present study aims to explore how leader–follower congruence in psychological capital (PsyCap) affects followers' task…

724

Abstract

Purpose

Based on the micro role transition theory (MRTT), the present study aims to explore how leader–follower congruence in psychological capital (PsyCap) affects followers' task performance and voice behavior, in which we uncover the mediating role of organizational embeddedness.

Design/methodology/approach

A survey was conducted in South China through a three-stage procedure, and finally, a dyad-structured sample of 62 leaders and 218 employees was matched. The polynomial regression method, response surface analysis and structural equation modeling were employed to test the effects of leader–follower PsyCap congruence.

Findings

(1) Followers' organizational embeddedness will be higher when leaders' and followers' PsyCap are more aligned; (2) followers' organizational embeddedness will be higher when leaders' and followers' PsyCap are aligned at a high level rather than when they are aligned at a low level; (3) followers' organizational embeddedness will be higher when followers' PsyCap is higher than leaders', compared to when followers' PsyCap is lower than leaders'; (4) organizational embeddedness mediates the relationship between leader–follower PsyCap congruence and followers' (a) task performance and (b) voice behavior.

Originality/value

This study emphasizes leaders' pivotal role in a process where followers' PsyCap affects task performance and voice behavior, and further extends MRTT through introducing organizational embeddedness as a mediator in such a mechanism.

Details

Leadership & Organization Development Journal, vol. 43 no. 4
Type: Research Article
ISSN: 0143-7739

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Article
Publication date: 27 January 2020

Renze Zhou, Zhiguo Xing, Haidou Wang, Zhongyu Piao, Yanfei Huang, Weiling Guo and Runbo Ma

With the development of deep learning-based analytical techniques, increased research has focused on fatigue data analysis methods based on deep learning, which are gaining in…

374

Abstract

Purpose

With the development of deep learning-based analytical techniques, increased research has focused on fatigue data analysis methods based on deep learning, which are gaining in popularity. However, the application of deep neural networks in the material science domain is mainly inhibited by data availability. In this paper, to overcome the difficulty of multifactor fatigue life prediction with small data sets,

Design/methodology/approach

A multiple neural network ensemble (MNNE) is used, and an MNNE with a general and flexible explicit function is developed to accurately quantify the complicated relationships hidden in multivariable data sets. Moreover, a variational autoencoder-based data generator is trained with small sample sets to expand the size of the training data set. A comparative study involving the proposed method and traditional models is performed. In addition, a filtering rule based on the R2 score is proposed and applied in the training process of the MNNE, and this approach has a beneficial effect on the prediction accuracy and generalization ability.

Findings

A comparative study involving the proposed method and traditional models is performed. The comparative experiment confirms that the use of hybrid data can improve the accuracy and generalization ability of the deep neural network and that the MNNE outperforms support vector machines, multilayer perceptron and deep neural network models based on the goodness of fit and robustness in the small sample case.

Practical implications

The experimental results imply that the proposed algorithm is a sophisticated and promising multivariate method for predicting the contact fatigue life of a coating when data availability is limited.

Originality/value

A data generated model based on variational autoencoder was used to make up lack of data. An MNNE method was proposed to apply in the small data case of fatigue life prediction.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 27 January 2020

Yongxin Zhou, Qian Li, Zhiguo Xing, Renze Zhou, Zhenhua Huang, Yanfei Huang and Weiling Guo

This paper aims to investigate the effect of aluminum addition on the microstructure and mechanical properties of Mg-8Gd-4Y-1Zn alloy.

145

Abstract

Purpose

This paper aims to investigate the effect of aluminum addition on the microstructure and mechanical properties of Mg-8Gd-4Y-1Zn alloy.

Design/methodology/approach

Mg-8Gd-4Y-1Zn-xAl (x = 0, 0.5, 1.0, 1.5, 2.0 Wt.%) alloys were prepared by the conventional gravity casting technology, and then microstructures, phase composition and mechanical properties were investigated by material characterization method, systematically.

Findings

Results show that the as-cast microstructure of Mg-8Gd-4Y-1Zn alloy mainly consists of a-Mg matrix as well as Mg12REZn (18 R LPSO structure), and island-like Mg3(RE, Zn) phase is distributed at the grain boundary. The addition of a small amount of Al (0.5 Wt.%) can decrease the content of island-like Mg3(RE, Zn) phase, but significantly increase the content of long-period stacking ordered (LPSO) structure, resulting in the improvement of both tensile strength and elongation of Mg-8Gd-4Y-1Zn alloy. However, the addition of excessive Al will consume Re element and decrease the amount of LPSO structure, leading to the decrease of tensile properties. When the content of Al is 0.5 Wt.%, the tensile strength and elongation are 225 MPa and 9.0% of Mg-8Gd-4Y-1Zn alloy, which are 14% and 29% higher than that of Mg-8Gd-4Y-1Zn alloy, respectively.

Originality/value

Adding aluminum to Mg-8Gd-4Y-1Zn alloy strengthens its mechanical properties. And the effect of Al content on the alloy strengthening. The formation mechanism of LPSO structure with different aluminum content was revealed.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 26 November 2024

Xuemei Wang, Jixiang He, Yue Ma, Hudie Zhao, Dongdong Zhang and Liang Yang

The purpose of this study is to evaluate the tea stem natural dye was extracted from tea stem waste and applied to dyeing silk fiber, after which the properties of dyed samples…

28

Abstract

Purpose

The purpose of this study is to evaluate the tea stem natural dye was extracted from tea stem waste and applied to dyeing silk fiber, after which the properties of dyed samples were tested and analyzed.

Design/methodology/approach

The dyeing process was optimized using the response surface methodology (RSM) approach. Dyeing temperature, pH and time were chosen as variables and the color difference value as a response. The properties of dyed samples were tested and analyzed.

Findings

The optimized dyeing process was as follows: dyeing temperature 70°C, pH 3.5 and time 110 min. The K/S and color difference value of silk fiber dyed with the optimal process dye enzymatic oxidation with laccase was 1.4 and 27.8, respectively. The silk fiber dyed has excellent color fastness, antioxidant and antibacterial property, which greatly increases the added value of the dyed products. Furthermore, the optimized dyeing process did not significantly affect the strength properties and handle of the silk fiber.

Originality/value

Researchers have not used statistical analysis to optimize the process of dyeing process of silk fiber by tea stem natural dye enzymatic oxidation with laccase using response surface methodology. Additionally, this dyeing process was a low-temperature dyeing process, which not only saves energy consumption and reduces silk fiber damage but also obtains superbly dyeing results and biological functional properties, achieve the effects of waste utilization and clean dyeing.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 June 2021

Yushen Wang, Wei Xiong, Danna Tang, Liang Hao, Zheng Li, Yan Li and Kaka Cheng

Traditional simulation research of geological and similar engineering models, such as landslides or other natural disaster scenarios, usually focuses on the change of stress and…

287

Abstract

Purpose

Traditional simulation research of geological and similar engineering models, such as landslides or other natural disaster scenarios, usually focuses on the change of stress and the state of the model before and after destruction. However, the transition of the inner change is usually invisible. To optimize and make models more intelligent, this paper aims to propose a perceptible design to detect the internal temperature change transformed by other energy versions like stress or torsion.

Design/methodology/approach

In this paper, micron diamond particles were embedded in 3D printed geopolymers as a potential thermal sensor material to detect the inner heat change. The authors use synthetic micron diamond powder to reinforced the anti-corrosion properties and thermal conductivity of geopolymer and apply this novel geopolymer slurry in the direct ink writing (DIW) technique.

Findings

As a result, the addition of micron diamond powder can greatly influence the rheology of geopolymer slurry and make the geopolymer slurry extrudable and suitable for DIW by reducing the slope of the viscosity of this inorganic colloid. The heat transfer coefficient of the micron diamond (15 Wt.%)/geopolymer was 50% higher than the pure geopolymer, which could be detected by the infrared thermal imager. Besides, the addition of diamond particles also increased the porous rates of geopolymer.

Originality/value

In conclusion, DIW slurry deposition of micron diamond-embedded geopolymer (MDG) composites could be used to manufacture the multi-functional geological model for thermal imaging and defect detection, which need the characteristic of lightweight, isolation, heat transfer and wave absorption.

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Article
Publication date: 26 August 2021

Daniel Eduardo Chavez and Haipeng (Allan) Chen

The purpose of this paper is to propose an overarching unifying theory where first-mover advantages are a conditional effect, not a main effect. By offering a closer look at how…

2107

Abstract

Purpose

The purpose of this paper is to propose an overarching unifying theory where first-mover advantages are a conditional effect, not a main effect. By offering a closer look at how the firm, market and product characteristics influence the supply and demand of innovations, this research furthers our understanding of the advantages and disadvantages for first movers.

Design/methodology/approach

This paper explores first-mover advantages as a conditional effect. Adopting a contingency perspective, the authors review the literature in marketing, strategic management, innovation and entrepreneurship to offer a conceptual framework putting innovation success at the core of first-mover advantages. The authors develop an inventory of propositions specifying how first-mover advantages depend on various firm features, market characteristics and product properties through their effects on the success of innovations.

Findings

A conceptual framework centered around innovation success yields testable hypotheses that are coherent with extant research on first-mover advantages and reconcile the seemingly contradictory evidence in that body of work.

Practical implications

This research provides managers with the opportunity to think about one of the most important decisions, i.e. time of entry, not as a linear finite decision, but instead as a flow with the innovations and potential for their success in mind.

Originality/value

This paper distinguishes itself from the existing literature with its focus on innovation within a contingency perspective for first-mover advantages.

Details

Journal of Business & Industrial Marketing, vol. 37 no. 6
Type: Research Article
ISSN: 0885-8624

Keywords

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