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Article
Publication date: 3 November 2021

Peng Cai, Chengpeng Xu, Fei Zheng, Jingfu Song and Gai Zhao

The purpose of this paper is to investigate the effect of lanthana (La2O3) on the mechanical and tribological properties of polyimide (PI).

Abstract

Purpose

The purpose of this paper is to investigate the effect of lanthana (La2O3) on the mechanical and tribological properties of polyimide (PI).

Design/methodology/approach

The mechanical and tribological properties of PI nanocomposites filled with La2O3 were studied by molecular dynamic simulations to explore the deep mechanisms from an atomic or molecular view.

Findings

The results showed that the hardness of the PI matrix increased after La2O3 modification with a decrease of 72.4% nanoindentation depth. Besides, the friction coefficient of PI decreased by 72.2% after filling La2O3, and the shear deformation was largely reduced under the same conditions. The adsorption effect of La2O3 on the PI molecular, which reduced the atomic relative concentration, velocity, interaction with counterpart Fe layer and the temperature rise in the frictional interface, contributed to the improvement of the mechanical and tribological performance.

Originality/value

This study reveals the friction and wear mechanism of PI composites filled with rare earth oxide at the nanoscale.

Details

Industrial Lubrication and Tribology, vol. 73 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 24 January 2020

Yuanhao Yu, Jingfu Song, Gai Zhao and Qingjun Ding

This paper aims to study the effect of different rare earth oxide on the tribological properties of polyimide (PI) nanocomposites based on the CNT and GO reinforcements.

Abstract

Purpose

This paper aims to study the effect of different rare earth oxide on the tribological properties of polyimide (PI) nanocomposites based on the CNT and GO reinforcements.

Design/methodology/approach

The PI nanocomposites filled with different rare earth oxide based on the carbon nanotubes and graphene oxide were designed and prepared by hot press sintering. The mechanical and tribological properties of PI nanocomposites were carried out, and their reinforcement mechanisms were discovered.

Findings

Rare earth oxide had a weak influence on the impact strength of PI nanocomposites. Filling La2O3 can dramatically reduce the friction coefficient and wear rate of PI nanocomposites.

Originality/value

The PI nanocomposites filled with rare earth oxide based on the CNT and GO reinforcements were designed, and their mechanical and tribological properties were studied.

Details

Industrial Lubrication and Tribology, vol. 72 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 5 July 2011

L.Z. Liu, L. Weng, Y.X. Song, L. Gao, H. Zhao and Q.Q. Lei

The purpose of this paper is to investigate the effects of coupling agents on the structure and properties of the nanocomposite films and clarify their mechanism…

Abstract

Purpose

The purpose of this paper is to investigate the effects of coupling agents on the structure and properties of the nanocomposite films and clarify their mechanism. Polyimide (PI)/Al2O3 nanocomposite films were prepared using different coupling agents.

Design/methodology/approach

Poly(amic acid) (PAA) was firstly synthesised from appropriate pyromellitic diannanocomposite and oxydianiline in N‐dimethylacetamide. Calculated amount of nano‐Al2O3 particles modified by different coupling agents (KH550, KH560, KH570 and AE3012) were added to PAA solution by an ultrasonic‐mechanical method and PI/nano‐Al2O3 film was fabricated by heat curing. The microstructure, thermal stability, mechanical properties and electric breakdown strength of the films were characterised.

Findings

The addition of coupling agents could greatly improve the dispersion homogeneity of Al2O3 nano‐particles in PI matrix. Results of corresponding characterisations indicated that both the thermal stability and mechanical properties of PI/Al2O3 nanocomposite film with KH550 were greater/better than others, while AE3012 could improve the electric breakdown strength.

Research limitations/implications

In the present discussion, the effects of different coupling agents, KH550, KH560, KH570 and AE3012, were investigated. Results of this research work would be beneficial to an in‐depth understanding on the relationship between microstructure and properties of PI composites, and further promote the development of the high‐performance PI insulating materials.

Originality/value

The four coupling agents, KH550, KH560, KH570 and AE3012, were firstly used to disperse the nano‐Al2O3 particles in PI matrix. The effects of coupling agents on microstructure and properties of composites were discussed by the authors in detail.

Article
Publication date: 15 July 2022

Halo Dalshad Omar, Auwal Abdulkadir, Md. Roslan Hashim and Mohd Zamir Pakhuruddin

This paper aims to present investigation on textured polyimide (PI) substrate for enhanced light absorption in flexible black silicon (bSi).

Abstract

Purpose

This paper aims to present investigation on textured polyimide (PI) substrate for enhanced light absorption in flexible black silicon (bSi).

Design/methodology/approach

Flexible bSi with thickness of 60 µm is used in this work. To texture the PI substrate, copper-seeding technique is used. A copper (Cu) layer with a thickness of 100 nm is deposited on PI substrate by sputtering. The substrate is then annealed at 400°C in air ambient for different durations of 60, 90 and 120 min.

Findings

With 90 min of annealing, root mean square roughness as large as 130 nm, peak angle of 24° and angle distribution of up to 87° are obtained. With this texturing condition, the flexible bSi exhibits maximum potential short-circuit current density (Jmax) of 40.33 mA/cm2, or 0.45 mA/cm2 higher compared to the flexible bSi on planar PI. The improvement is attributed to enhanced light scattering at the flexible bSi/textured PI interface. The findings from this work demonstrate that the optimization of the PI texturing via Cu-seeding process leads to an enhancement in the long wavelengths light absorption and potential Jmax in the flexible bSi absorber.

Originality/value

Demonstrated enhanced light absorption and potential Jmax in flexible bSi on textured PI substrate (compared to planar PI substrate) by Cu-seeding with different annealing durations.

Details

Microelectronics International, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1356-5362

Keywords

Abstract

Details

Functional Structure and Approximation in Econometrics
Type: Book
ISBN: 978-0-44450-861-4

Book part
Publication date: 1 October 2007

Mattias Ganslandt and Keith E. Maskus

The existence of parallel imports (PI) raises a number of interesting policy and strategic questions, which are the subject of this survey article. For example, parallel…

Abstract

The existence of parallel imports (PI) raises a number of interesting policy and strategic questions, which are the subject of this survey article. For example, parallel trade is essentially arbitrage within policy-integrated markets of IPR-protected goods, which may have different prices across countries. Thus, we analyze fully two types of price differences that give rise to such arbitrage. First is simple retail-level trade in horizontal markets because consumer prices may differ. Second is the deeper, and more strategic, issue of vertical pricing within the common distribution organization of an original manufacturer selling its goods through wholesale distributors in different markets. This vertical price control problem presents the IPR-holding firm a menu of strategic choices regarding how to compete with PI. Another strategic question is how the existence of PI might affect incentives of IPR holders to invest in research and development (R&D). The global research-based pharmaceutical firms, for example, strongly oppose any relaxation of restrictions against PI of drugs into the United States, arguing that the potential reduction in profits would diminish their ability to innovate. There is a close linkage here with price controls for medicines, which are a key component of national health policies but can give rise to arbitrage through PI. We also discuss the complex economic relationships between PI and other forms of competition policy, or attempts to limit the abuse of market power offered by patents and copyrights. Finally, we review the emerging literature on how policies governing PI may affect international trade agreements.

Details

Intellectual Property, Growth and Trade
Type: Book
ISBN: 978-1-84950-539-0

Article
Publication date: 23 May 2022

Hao Luo, Yilun Wang and Zhixing Luo

The paper aims to study the challenges and solutions of city logistics in the new retail era. The new retail, which is characterized by omni-channel, fragmented orders and…

Abstract

Purpose

The paper aims to study the challenges and solutions of city logistics in the new retail era. The new retail, which is characterized by omni-channel, fragmented orders and decentralized 2C distribution, is becoming the mainstream of the retail industry worldwide. In order to achieve a comprehensive breakthrough in new retail, the change of order fulfillment mode is the most noteworthy issue. The aim of this paper is to design a city logistics operation model for new retail and verify its feasibility and efficiency.

Design/methodology/approach

A physical internet (PI) enabled two-tier city logistics solution is proposed by redefining the key facilities in city logistics with the PI concept. A “Container-as-a-Warehouse” operation mode is designed to provide a more flexible store and transfer solution. A mathematical model of the proposed solution is established. An adaptive large neighborhood search (ALNS) is designed based upon an iterative procedure, which ensures consistent and optimal results.

Findings

To quantitatively assess the feasibility of the proposed solution, a computational experiment is designed to compare the performance of the proposed model against the conventional two-tier city logistics operation. The effects of geographical location pattern, utilization of PI-hub as well as the fluctuation of customer orders are analyzed. The results show that the PI-enabled city logistics is more advantageous than the conventional solution.

Research limitations/implications

This study does not consider the impact of new technologies in city logistics; for example, the replenishment problem of unmanned vending machines and the charging problem of electric vehicles.

Practical implications

The proposed PI-enabled solution and analysis results in this paper have positive guiding significance for future practical application.

Originality/value

Based on the concept of PI, this paper proposes an innovative and practical operation model to solve the city logistics challenges.

Details

Industrial Management & Data Systems, vol. 122 no. 6
Type: Research Article
ISSN: 0263-5577

Keywords

Article
Publication date: 19 January 2022

Shoufeng Ji, Yaoting Xue and Guosong Zhu

The Physical Internet (PI) application in a supply chain is explored by automakers to achieve a digital supply chain to challenge timely delivery while maintaining high…

53

Abstract

Purpose

The Physical Internet (PI) application in a supply chain is explored by automakers to achieve a digital supply chain to challenge timely delivery while maintaining high customised production at the lowest operating cost.

Design/methodology/approach

A bi-objective mixed integer model is formulated, where production is performed in multistage manufacturing systems (MMS) and then delivered in a two-level distribution system. Next, a hybrid iterative method algorithm is developed to solve the practical-scale problem within an admissible time. Finally, PI's benefits on production and supply chain operation are discussed through extensive computational experiments in different supply chain configurations.

Findings

Three significant findings are obtained. First, PI can achieve a comparable or better service level, while the cost is always lower. Second, PI can improve the utilisation of production and transportation resources. Third, with a more complex supply chain and a higher production cost or truck fixed cost, PI's advantages over traditional supply chain become more vigorous, but the increase in orders will weaken it.

Practical implications

The auto enterprise should adopt a PI-enabled supply chain (PI-SC), especially with the increase of network complexity and specific cost factors.

Social implications

Importance should be attached to the PI-SC to make customers better involved in the supply chain.

Originality/value

First, the application of PI in the existing plant is described. Second, MMS production with multi-mode transportation is jointly scheduled. Third, the decision support of the PI-SC is provided for auto enterprises.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 23 February 2022

Mohamad Gharib

Most developed countries have enacted privacy laws to govern the collection and use of personal information (PI) as a response to the increased misuse of PI. Yet, these…

Abstract

Purpose

Most developed countries have enacted privacy laws to govern the collection and use of personal information (PI) as a response to the increased misuse of PI. Yet, these laws rely heavily on the concept of informational self-determination through the “notice” and “consent” models, which is deeply flawed. This study aims at tackling these flaws achieve the full potential of these privacy laws.

Design/methodology/approach

The author critically reviews the concept of informational self-determination through the “notice” and “consent” model identifying its main flaws and how they can be tackled.

Findings

Existing approaches present interesting ideas and useful techniques that focus on tackling some specific problems of informational self-determination but fail short in proposing a comprehensive solution that tackles the essence of the overall problem.

Originality/value

This study introduces a model for informed consent, a proposed architecture that aims at empowering individuals (data subjects) to take an active role in the protection of their PI by simplifying the informed consent transaction without reducing its effectiveness, and an ontology that can partially realize the proposed architecture.

Details

Information & Computer Security, vol. 30 no. 4
Type: Research Article
ISSN: 2056-4961

Keywords

Article
Publication date: 26 January 2022

Anshuman Sharma, Akinola Fadahunsi, Haidar Abbas and Vivek Kumar Pathak

Based on the stimulus-organism-response (SOR) framework, this study aims to investigate the effect of social media marketing (SMM) activities on consumers’ purchase…

1096

Abstract

Purpose

Based on the stimulus-organism-response (SOR) framework, this study aims to investigate the effect of social media marketing (SMM) activities on consumers’ purchase intention (PI), as well as to test the mediation effect of consumer-based brand equity (CBBE) and consumer inspiration (INS) between the relationship of SMM and PI. Further, this study has also proposed and validated SMM as a reflective–formative higher-order construct (R-F-HOC) with its five first-order dimensions: customization, entertainment, interaction, trendiness and word of mouth (WoM).

Design/methodology/approach

Using a non-probability purposive sampling method, a structured questionnaire survey using Google forms was used to collect data from a sample of 236 UAE consumers. Subsequently, the data was analyzed with a hybrid method that combined partial least squares structural equation modeling (PLS-SEM) and artificial neural network (ANN) analysis.

Findings

The findings suggest that SMM has a direct effect on CBBE, INS and PI. Both proposed mediation effects are statistically significant, and there is a partial complementary mediation effect of CBBE and INS between SMM and PI. This study validated the operationalization of SMM as R-F-HOC. Further, the results of the ANN analysis validate the results of the PLS-SEM, suggesting that SMM is the strongest predictor of PI followed by CBBE and INS.

Research limitations/implications

In terms of theoretical significance, this study has advanced our understanding of the process by which the influence of SMM is transferred to PI via CBBE and INS. This study has also made a significant contribution by validating SMM as a R-F-HOC. In terms of practical implications, this study suggests that SMM should be best assessed as a R-F-HOC construct with five dimensions: customization, entertainment, interaction, trendiness and WoM. This study has also demonstrated the importance of CBBE and INS in transmitting the effect of SMM on PI to marketers.

Originality/value

This study contributes to the digital advertising literature by filling a knowledge gap about the mediation effect of CBBE and INS between SMM and PI via the SOR framework. SMM’s multidimensionality as a R-F-HOC has also been established.

1 – 10 of over 7000