Search results

1 – 4 of 4
Article
Publication date: 9 August 2021

Haijie Yu, Haijun Wei, Daping Zhou, Jingming Li and Hong Liu

This study aims to reconstruct the frictional vibration signal from noise and characterize the running-in process by frictional vibration.

Abstract

Purpose

This study aims to reconstruct the frictional vibration signal from noise and characterize the running-in process by frictional vibration.

Design/methodology/approach

There is a strong correlation between tangential frictional vibration and normal frictional vibration. On this basis, a new frictional vibration reconstruction method combining cross-correlation analysis with ensemble empirical mode decomposition (EEMD) was proposed. Moreover, the concept of information entropy of friction vibration is introduced to characterize the running-in process.

Findings

Compared with the wavelet packet method, the tangential friction vibration and the normal friction vibration reconstructed by the method presented in this paper have a stronger correlation. More importantly, during the running-in process, the information entropy of friction vibration gradually decreases until the equilibrium point is reached, which is the same as the changing trend of friction coefficient, indicating that the information entropy of friction vibration can be used to characterize the running-in process.

Practical implications

The study reveals that the application EEMD method is an appropriate approach to reconstruct frictional vibration and the information entropy of friction vibration represents the running-in process. Based on these results, a condition monitoring system can be established to automatically evaluate the running-in state of mechanical parts.

Originality/value

The EEMD method was applied to reconstruct the frictional vibration. Furthermore, the information entropy of friction vibration was used to analysis the running-in process.

Details

Industrial Lubrication and Tribology, vol. 73 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 5 March 2018

Daniele B. Vinholes, Carlos Alberto Machado, Hilton Chaves, Sinara L. Rossato, Ione M.F. Melo, Flavio D. Fuchs and Sandra C. Fuchs

A staff canteen in the workplace can offer a healthier diet, which may lower the blood pressure (BP). The purpose of this paper is to evaluate whether the presence of staff…

Abstract

Purpose

A staff canteen in the workplace can offer a healthier diet, which may lower the blood pressure (BP). The purpose of this paper is to evaluate whether the presence of staff canteen in the workplace is associated with consumption of healthy food and lower systolic and diastolic BP.

Design/methodology/approach

A cross-sectional study was conducted, randomly selecting workers through a multistage sampling, stratified by company size in Brazil. Demographic, socioeconomic, and life style characteristics were evaluated, and weight, height, and BP were measured. Statistical analysis used generalized linear models, controlling for design effect and confounding factors, to assess the association between BP and staff canteen and the intake of food items.

Findings

In total, 4.818 workers, aged 35.4±10.7 years, 76.5 percent men, with 8.7±4.1 years of formal education were enrolled. Prevalence of hypertension was 24.7 percent (p-value <0.001) among workers from industries with staff canteen vs 30.6 percent among those with no staff canteen. Workers of industries with staff canteen consumed higher proportion of fruits, green leafy vegetables, and milk than workers of industries without canteen, and had lower systolic and diastolic BP, independently of the frequency of intake.

Practical implications

Workers of industries with staff canteen consumed a healthier diet, and had lower systolic and diastolic BP, and lower prevalence of hypertension than workers from workplaces without staff canteen.

Originality/value

This study was the first carried out among workers of industries reporting that the presence of a staff canteen in the workplace is associated with lower systolic and diastolic BP and prevalence of hypertension.

Details

British Food Journal, vol. 120 no. 3
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 2 May 2017

Peter Lukacs, Alena Pietrikova and Pavol Cabuk

The purpose of this paper is to find optimal sintering conditions of silver-based nano-inks for achieving the high electrical conductivity of the deposited layers applied on…

Abstract

Purpose

The purpose of this paper is to find optimal sintering conditions of silver-based nano-inks for achieving the high electrical conductivity of the deposited layers applied on polyimide foils as well as the influence of ageing on the electrical conductivity. Therefore, the investigation in the field of silver layers deposited by inkjet printing technology is presented in this paper.

Design/methodology/approach

The four-point resistance measurements were realized for a detailed and precise analysis of the resistance of two different silver layers under different sintering conditions depending on the type of nano-ink varied about the recommended values. Highly accelerated stress tests (HASTs) were also applied as an ageing method for confirmation of the high electrical stability of the silver layers.

Findings

The results prove the strong influence of the temperature and the time of the sintering process on the sheet resistance of the investigated silver-based layers deposited by inkjet printing technology on polyimide foils. The HASTs caused significant changes in the electrical conductivity for both nano-inks presented in this paper. The existence of noticeable dependence among the resistivity, thermal treatment and ageing was proved.

Originality/value

The main benefit lays in the optimization of sintering conditions to improve the electrical conductivity of the silver layers. The paper also presents a new approach for a stability analysis of the silver layers by HASTs.

Details

Circuit World, vol. 43 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 6 February 2017

Peter Lukacs, Alena Pietrikova, Beata Ballokova, Dagmar Jakubeczyova and Ondrej Kovac

This paper aims to find the optimal deposition conditions for achieving the homogenous structure of the silver layers onto three types of polymeric substrates as well as on the…

Abstract

Purpose

This paper aims to find the optimal deposition conditions for achieving the homogenous structure of the silver layers onto three types of polymeric substrates as well as on the rigid substrates. For this reason, the detailed investigation of the silver-based layers deposited at different technological conditions by microscopic methods is presented in this paper.

Design/methodology/approach

The special test pattern has been designed and deposited at different substrate temperatures by using two types of generally available silver-based nano-inks. Cross-sections and 3D profiles of the deposited silver layers have been profoundly analysed by using the optical profiler Sensofar S Neox on the generally used polymeric (PI, PET and PEN) and rigid substrates (951 and 9K7 LTCC, glass and alumina).

Findings

The results prove the strong correlation between the substrate temperature during the deposition process and the final shape of the created structure which has the a direct impact on the layers’ homogeneity. The results also prove the theory of the coffee ring effect creation in the inkjet printing technology.

Originality/value

The main benefit of this paper lies in the possibility of the homogeneity achievement of the deposited silver-based layers on the several polymeric and rigid substrates by managing the temperature during the deposition. The paper also offers the comparative study of nano-inks’ behaviour on several polymeric and rigid substrates.

Details

Circuit World, vol. 43 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

1 – 4 of 4