Li Yinghui, Chunping Xie and Xinjin Liu
The purpose of this paper is to know airflow field and its distribution of pneumatic compact spinning systems. Complete compact spinning (CCS) and four-line rollers compact…
Abstract
Purpose
The purpose of this paper is to know airflow field and its distribution of pneumatic compact spinning systems. Complete compact spinning (CCS) and four-line rollers compact spinning (FRCS) are both two kinds of pneumatic compact spinning systems, which utilizes airflow in condensing equipment to condense fiber bundle and improve yarn properties.
Design/methodology/approach
The paper opted for an exploratory study using finite element method, the airflow field in the condensing area of CCS and FRCS were simulated. First, a periodic movement of the fibers in bundle in condensing area was detected, and the yarn tracks were described veritably under the high-speed-video-camera and AutoCAD Software. Then the physical models of the condensing zone were constructed according to the physical parameters of the practical system. The simulation of airflow velocities were extracted along the yarn tracks using ANSYS Software. Finally, the numerical results were verified by spinning experiments.
Findings
The results show that the negative velocity component along the Y-axis helps keeping beneficial hairiness. CCS has higher negative velocity value and more abundant beneficial hairiness than FRCS. The velocity component in the X-axis direction has a direct effect on yarn evenness. For the same liner density of CCS and FRCS, the larger the value of the velocity component on X-axis is, the better the yarn evenness is. For 9.7tex, CCS has larger velocity component in the X-axis direction and better yarn evenness than FRCS, showing that CCS is more suitable for spinning fine count yarn. The velocity component in the Z-axis direction has a direct effect on breaking strength. CCS has little velocity component in the Z-axis direction and little breaking strength than FRCS.
Originality/value
To know airflow field and its distribution by finite element method is helpful to investigate the condensing principles of the fiber bundle and improve yarn properties.
Details
Keywords
Gang Ma, Rui Yang, Aarren Minneyfield, Xieting Gu, Yinghui Gan, Lin Li, Sixia Liu, Wenjun Jiang, Weiguo Lai and Yihua Wu
The purpose of this paper is to contribute to the literature of blended learning by practically implementing best practices in employee training.
Abstract
Purpose
The purpose of this paper is to contribute to the literature of blended learning by practically implementing best practices in employee training.
Design/methodology/approach
In response to the Covid-19 pandemic, an organization had modified its training procedures over the course of three years to improve employee and organizational outcomes. Employee candidates who were onboarded into sales positions during the years 2019–2021 were given the opportunity to learn the content in an online format and subsequently evaluated prior to their in-person training and final evaluation to provide them with a self-paced blended learning experience. Both evaluation scores, along with the length it took to complete the trainings, were used to determine the trainings effectiveness and efficiency respectively.
Findings
The findings for the study showed that the organization was successfully able to improve upon the efficiency of the training by reducing training length and the effectiveness by improving employee outcomes.
Research limitations/implications
The study’s design was limited to the probation process, which resulted in issues drawing conclusions for employee outcomes that were relevant to their long-term organizational success. This emphasizes the importance of comprehensive investigations for future practical studies.
Practical implications
The findings allow for the improvement of blended learning models within real-world organizational contexts that provide organizations with the opportunity to improve employee outcomes while reducing time costs.
Originality/value
This study provides data from applied blended learning procedures that were validated using empirical findings, which contributes to the practicality of blended learning in workplace training.
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Yang Yang, Yinghui Tian, Runyu Yang, Chunhui Zhang and Le Wang
The objective of this paper is to quantitatively assess shear band evolution by using two-dimensional discrete element method (DEM).
Abstract
Purpose
The objective of this paper is to quantitatively assess shear band evolution by using two-dimensional discrete element method (DEM).
Design/methodology/approach
The DEM model was first calibrated by retrospectively modelling existing triaxial tests. A series of DEM analyses was then conducted with the focus on the particle rotation during loading. An approach based on particle rotation was developed to precisely identify the shear band region from the surrounding. In this approach, a threshold rotation angle ω0 was defined to distinguish the potential particles inside and outside the shear band and an index g(ω0) was introduced to assess the discrepancy between the rotation response inside and outside shear band. The most distinct shear band region can be determined by the ω0 corresponding to the peak g(ω0). By using the proposed approach, the shear band development of two computational cases with different typical localised failure patterns were successfully examined by quantitatively measuring the inclination angle and thickness of shear band, as well as the microscopic quantities.
Findings
The results show that the shear band formation is stress-dependent, transiting from conjugated double shear bands to single shear band with confining stress increasing. The shear band evolution of two typical localised failure modes exhibits opposite trends with increasing strain level, both in inclination angle and thickness. Shear band featured a larger volumetric dilatancy and a lower coordination number than the surrounding. The shear band also significantly disturbs the induced anisotropy of soil.
Originality/value
This paper proposed an approach to quantitatively assess shear band evolution based on the result of two-dimensional DEM modelling.
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Yufu Xu, Kequn Sun, Quan Zheng, Lulu Yao, Yinghui Dong and Ruhong Song
This paper aims to offeri novel nano-additives polymer microgels to precisely improve the lubrication properties of titanium alloy under different temperatures.
Abstract
Purpose
This paper aims to offeri novel nano-additives polymer microgels to precisely improve the lubrication properties of titanium alloy under different temperatures.
Design/methodology/approach
The surfactant-free emulsion polymerization method was used to prepare Poly(N-isoprolylacrylamide) (PNIPAM) microgels. A ball-on-disk tribometer was applied to investigated the temperature-sensitive lubrication behavior of PNIPAM microgels.
Findings
The results show that the as-prepared microgels are ball-like nanoparticles with the size of 50–900 nm. In addition, potassium persulfate as initiator, complete mixing technic and high sodium dodecyl sulfate (SDS) concentration contribute to the formation of microgels with small size. The tribosystem shows a lower friction coefficient with the lubrication of PNIPAM microgels as aqueous solution additives when the temperature exceeding the critical temperature.
Originality/value
This work reports the temperature-sensitive lubrication of PNIPAM microgels. The critical temperature of PNIPAM microgels could be regulated by the addition of SDS in the solutions. This offers an effective and facile strategy for regulation of the critical temperature of smart microgels, which is helpful for the smart lubrication in the future.
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The purpose of this study is to investigate the effects of air-suction slots geometry on the condensing zone of pneumatic compact spinning.
Abstract
Purpose
The purpose of this study is to investigate the effects of air-suction slots geometry on the condensing zone of pneumatic compact spinning.
Design/methodology/approach
This paper investigated the condensing zone of pneumatic compact spinning with perforated drum for different structures of air-inlet slot geometry with computational fluid dynamics. For this purpose, three air-suction guides with different air-slots were designed. To create the condensing zone for the numerical simulation, a suction insert and the perforated drum were also designed. Flow velocity components on the X, Y, and Z axes, static pressure distribution and the streamline diagram were used for comparative analysis. Designed air-suction guides were produced with a 3D printer and used for yarn production.
Findings
Numerical simulation results showed that condensing effects were provided for all three types of air-suction guides and approaching air-slots on the suction guides resulted in greater flow components but may cause fluctuations. Experimental results also showed that actual flow velocity components (Z-axis) are effective on hairiness (H) properties of the yarn while assisting flow-velocity components are more effective on the evenness and tenacity properties of the yarn.
Originality/value
This paper presents the numerical flow field simulation of compact spinning for different structures of air-suction guides with detailed measurements. To know the effects of air-suction guides on the condensing zone may be helpful to improve yarn properties. In addition, a 3D printer was used for the production of designed parts.
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Bing Shi, Dan Zhang, Hongling Xie and Yinghui Zhou
This study aims to examine factors affecting Chinese adolescents’ purchase intention for local brands; this study focuses on the effects of perceived social status value and…
Abstract
Purpose
This study aims to examine factors affecting Chinese adolescents’ purchase intention for local brands; this study focuses on the effects of perceived social status value and materialistic values.
Design/methodology/approach
A theoretical model relating perceived social status value of brands to purchase intention, including materialistic values as a moderator, was developed and tested, using a sample of 587 Chinese adolescent respondents. Another experimental study examined the variability of the moderation of materialistic values across different levels of peer pressure in a product usage occasion.
Findings
Perceived social status value associated with local and foreign brands significantly influences purchase intention for local brands. Moreover, influence of perceived social status value of local versus foreign brands on local brand purchase intention is greater for materialistic adolescents. Additionally, the moderation of materialistic values is found in a product usage occasion with high peer pressure, but not in an occasion with low peer pressure.
Research limitations/implications
The findings show that perceived social status value associated with brands shapes purchase intention for local brands. The moderating effect of materialistic values is complex and suggests further research. The study’s scope is limited to Chinese adolescents.
Practical implications
The findings provide understanding of the drivers of purchase intention, and thus serve as a guideline for Chinese firms and foreign marketers seeking to enter the growing Chinese market, as well as consumer educators in China.
Originality/value
This study contributes to the limited empirical research into the factors shaping country-of-origin effects. Moreover, the findings suggest the need to consider the moderating role of materialistic values on purchase intention for local brands.
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Aimin Yan, Yicong Sun, Sarah Brooks, Yinghui Zhang and Jinyun Duan
Drawing on the generativity framework, this study aims to investigate the relationship between the Dark Triad personalities (Machiavellianism, narcissism, and psychopathy) and…
Abstract
Purpose
Drawing on the generativity framework, this study aims to investigate the relationship between the Dark Triad personalities (Machiavellianism, narcissism, and psychopathy) and knowledge hiding. This study also identifies the mediating role of generativity motivation and the moderating role of focus on opportunities.
Design/methodology/approach
Using a convenience sample, a two-wave time-lagged study collected survey responses from 498 employees from manufacturing industries in China, and the data was analyzed using hierarchal regression and bootstrapping methods.
Findings
This study found that Machiavellianism and psychopathy are both positively related to generativity motivation. The generativity motivation plays a mediating role in the paths of Machiavellianism and psychopathy on knowledge hiding, and a focus on opportunities positively moderates the direct and indirect effect of Machiavellianism and psychopathy on knowledge hiding.
Originality/value
Based on the generativity framework, we find a new underlying mechanism between the Dark Triad personalities and knowledge hiding, thereby further enriching the literature in relation to their influence over knowledge management. Moreover, it also finds that a focus on opportunities can weaken the negative relationships between the Dark Triad personalities and knowledge hiding.
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Liwen Feng, Xiangyan Ding, Yinghui Zhang, Ning Hu and Xiaoyang Bi
The study delves into the influence of wear cycles on these parameters. The purpose of this paper is to identify characteristic patterns of σRS and εPEEQ that discern varying wear…
Abstract
Purpose
The study delves into the influence of wear cycles on these parameters. The purpose of this paper is to identify characteristic patterns of σRS and εPEEQ that discern varying wear situations, thereby contributing to the enrichment of wear theory. Furthermore, the findings serve as a foundational basis for nondestructive and in situ wear detection methodologies, such as nonlinear ultrasonic detection, known for its sensitivity to σRS and εPEEQ.
Design/methodology/approach
This paper elucidates the wear mechanism through the lens of residual stress (σRS) and plastic deformation within distinct fretting regimes, using a two-dimensional cylindrical/flat contact model. It specifically explores the impact of the displacement amplitude and cycles on the distribution of residual stress and equivalent plastic strain (εPEEQ) in both gross slip regime and partial slip regimes.
Findings
Therefore, when surface observation of wear is challenging, detecting the σRS trend at the center/edge, region width and εPEEQ distribution, as well as the maximum σRS distribution along the depth, proves effective in distinguishing wear situations (partial or gross slip regimes). However, discerning wear situations based on εPEEQ along the depth direction remains challenging. Moreover, in the gross slip regime, using σRS distribution or εPEEQ along the width direction rather than the depth direction can effectively provide feedback on cycles and wear range.
Originality/value
This work introduces a novel perspective for investigating wear theory through the distribution of residual stress (σRS) and equivalent plastic strain (εPEEQ). It presents a feasible detection theory for wear situations using nondestructive and in situ methods, such as nonlinear ultrasonic detection, which is sensitive to σRS and εPEEQ.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2024-0005/
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Shaoyu Zeng, Yinghui Wu and Yang Yu
The paper formulates a bi-objective mixed-integer nonlinear programming model, aimed at minimizing the total labor hours and the workload unfairness for the multi-skilled worker…
Abstract
Purpose
The paper formulates a bi-objective mixed-integer nonlinear programming model, aimed at minimizing the total labor hours and the workload unfairness for the multi-skilled worker assignment problem in Seru production system (SPS).
Design/methodology/approach
Three approaches, namely epsilon-constraint method, non-dominated sorting genetic algorithm 2 (NSGA-II) and improved strength Pareto evolutionary algorithm (SPEA2), are designed for solving the problem.
Findings
Numerous experiments are performed to assess the applicability of the proposed model and evaluate the performance of algorithms. The merged Pareto-fronts obtained from both NSGA-II and SPEA2 were proposed as final solutions to provide useful information for decision-makers.
Practical implications
SPS has the flexibility to respond to the changing demand for small amount production of multiple varieties products. Assigning cross-trained workers to obtain flexibility has emerged as a major concern for the implementation of SPS. Most enterprises focus solely on measures of production efficiency, such as minimizing the total throughput time. Solutions based on optimizing efficiency measures alone can be unacceptable by workers who have high proficiency levels when they are achieved at the expense of the workers taking more workload. Therefore, study the tradeoff between production efficiency and fairness in the multi-skilled worker assignment problem is very important for SPS.
Originality/value
The study investigates a new mixed-integer programming model to optimize worker-to-seru assignment, batch-to-seru assignment and task-to-worker assignment in SPS. In order to solve the proposed problem, three problem-specific solution approaches are proposed.