Water-lubricated ceramic components are promising material combinations for tribological applications because they are wear-resistant and can exhibit low coefficients of friction under different loads. The aim of the work was to show in model tribological experiments with silicon nitride that the lubricating properties of water can be improved by adding water-soluble ionic liquids. The geometry used and the experimental parameters were selected to approximately simulate a piston ring/cylinder liner contact. We found that the addition of 1 % IL tributyl methyl phosphonium acetate[P4441][OAc] leads to a reduction of the maximum friction work by 58 % compared to pure water lubrication and even by 96 % compared to oil lubricated steel. It was shown that suitable running-in conditions and sufficient cooling by the lubricant at an early stage are important prerequisites for achieving low friction and wear values. In addition, the chemical interaction of water and IL with silicon nitride strongly affects the tribological behavior. As increasing demands on sustainability (green tribology) become more and more important due to environmental aspects, this work provides important insights for the development of novel water-based lubricant systems.

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This paper presents basic concepts and enabling technologies for a mobile plastering robot used on the construction site and controlled by a skilled operator. Economic aspects of the German plastering industry, requirements for semi-automated plastering, alternative robotic end-effectors, various kinematic structures as well as suitable drive technologies for a plastering robot are discussed in detail.

The article deals with the appropriation of pre-modern Chinese sources by R. Nicholl and others for the national history of Brunei. It provides an analysis of the relevant sources and argues that Poli, a country described in the Chinese texts, was not a precursor of Brunei.

The present essay deals with the fabrication of the imperial genealogy of the Southern Tang state (937–976). A means of linking the Southern Tang founder Li Bian (r. 937–943) to the Tang, it helped establish Southern Tang claims to the Tang heritage. Though no original fabricated genealogy survives, variant forms have been handed down through a number of texts starting in the early Northern Song period. These are discussed in terms of their plausibility, marking the Jiang- nan lu (979) by Xu Xuan (916–991) as the officially accepted description and the Zizhi tongjian (1184) version as the most “believable” of all fake Southern Tang genealogies.