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Article
Publication date: 2 May 2008

Xiaodong Zhou, Huaqiang Shi, Xun Fu, Danmei Wu and Zhengshui Hu

The purpose of this paper is to investigate the tribological properties of MoS2 nano‐sized hollow spheres in liquid paraffin (LP) and the corresponding action mechanism…

Abstract

Purpose

The purpose of this paper is to investigate the tribological properties of MoS2 nano‐sized hollow spheres in liquid paraffin (LP) and the corresponding action mechanism. Morever, its feasibity of industrial application as an oil additive in the industrial lubrication field is also explored.

Design/methodology/approach

The tribological properties of MoS2 nano‐sized hollow spheres (NH‐MoS2) modified by Cyanex 301(di‐(2,4,4‐trimethylpentyl) dithiophosphinic acid) with size of 200 ∼ 300 nm in LP are studied and compared with those of the commercial colloidal MoS2 (CC‐MoS2) on a four‐ball tester and an Optimol SRV Oscillating friction and wear tester in a ball‐on disk configuration. The worn surfaces of the lower flat disc are examined with a scanning electron microscopy and an X‐ray photoelectron spectroscopy, respectively.

Findings

Results show that NH‐MoS2 is a better extreme‐pressure additive and anti‐wear (AW) and friction‐reducing additive in LP than CC‐MoS2. Under the optimum concentration of 0.5 per cent for both NH‐MoS2 and CC‐MoS2 and the load of 400 N, the friction coefficient of NH‐MoS2 + LP and CC‐MoS2 + LP decreases about 43.8 and 6.3 per cent, and the wear volume loss decreases about 60.3 and 12.0 per cent compared with the pure LP. The boundary lubrication mechanism for NH‐MoS2 + LP can be deduced as the effective chemical adsorption protective film formed by the long chain alkyls R and active elements (S and P) in the modification layer and tribochemical reaction film containing the tribochemical products of the additive. Moreover, sliding and rolling frictions co‐exist in NH‐MoS2 + LP, doing contributions to the good tribological properties as well.

Originality/value

In this paper, the Cyanex 301‐modified MoS2 nano‐sized hollow spheres with diameter of 200 ∼ 300 nm are firstly added into LP to investigate its tribological properties. The excellent AW and friction‐reducing properties indicate that this MoS2 hollow spheres product is a good oil additive, and the fundamental data presented here will be useful for its further industrial application in the future.

Details

Industrial Lubrication and Tribology, vol. 60 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 15 May 2020

Feifei Bian, Danmei Ren, Ruifeng Li, Peidong Liang, Ke Wang and Lijun Zhao

The purpose of this paper is to enable robots to intelligently adapt their damping characteristics and motions in a reactive fashion toward human inputs and task…

Abstract

Purpose

The purpose of this paper is to enable robots to intelligently adapt their damping characteristics and motions in a reactive fashion toward human inputs and task requirements during physical human–robot interaction.

Design/methodology/approach

This paper exploits a combination of the dynamical system and the admittance model to create robot behaviors. The reference trajectories are generated by dynamical systems while the admittance control enables robots to compliantly follow the reference trajectories. To determine how control is divided between the two models, a collaborative arbitration algorithm is presented to change their contributions to the robot motion based on the contact forces. In addition, the authors investigate to model the robot’s impedance characteristics as a function of the task requirements and build a novel artificial damping field (ADF) to represent the virtual damping at arbitrary robot states.

Findings

The authors evaluate their methods through experiments on an UR10 robot. The result shows promising performances for the robot to achieve complex tasks in collaboration with human partners.

Originality/value

The proposed method extends the dynamical system approach with an admittance control law to allow a robot motion being adjusted in real time. Besides, the authors propose a novel ADF method to model the robot’s impedance characteristics as a function of the task requirements.

Details

Industrial Robot: the international journal of robotics research and application, vol. 47 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 25 August 2020

Banasree Dey, Jones Mathew and Chin Chee-Hua

Rural homestays have emerged as an interesting option for tourists. This study aims to assess the role of destination attractiveness factors and travel motivations in…

Abstract

Purpose

Rural homestays have emerged as an interesting option for tourists. This study aims to assess the role of destination attractiveness factors and travel motivations in homestay choice. The moderating role of need for uniqueness towards enhancing these relationships is also examined.

Design/methodology/approach

A survey of 201 Indian tourists who had visited rural homestays in the Uttarakhand state of India was conducted. Data were analyzed using SPSS and WarpPLS, based on structural equation modelling approach.

Findings

Results indicate that two destination attractiveness factors – (a) cultural and rural attractions and (b) destination location and transportation – have a significant association with rural homestay choice. Further, need for uniqueness enhances the relationship between natural attractions and choosing rural homestays.

Originality/value

Although there are several studies on rural homestays, there is scant research on the factors influencing the choice of rural homestays from a tourists’ perspective. Besides, studies on rural homestay tourism have not assessed the role of need for uniqueness in influencing such choices. The implications of the study for destination marketers, homestay operators and owners are discussed which would hopefully aid in attracting discerning tourists to the rural homestays to such regions.

Details

International Journal of Culture, Tourism and Hospitality Research, vol. 14 no. 4
Type: Research Article
ISSN: 1750-6182

Keywords

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