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Effect of Background Music on Maximum Acceptable Weight of Manual Lifting Tasks

Yu R.

International Journal of Occupational Safety and Ergonomics

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2014

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Vol. 20, No. 3

437--445

EN

This study used the psychophysical approach to investigate the impact of tempo and volume of background music on the maximum acceptable weight of lift (MAWL), heart rate (HR) and rating of perceived exertion (RPE) of participants engaged in lifting. Ten male college students participated in this study. They lifted a box from the floor, walked 1–2 steps as required, placed the box on a table and walked back twice per minute. The results showed that the tempo of music had a significant effect on both MAWL and HR. Fast tempo background music resulted in higher MAWL and HR values than those resulting from slow tempo music. The effects of both the tempo and volume on the RPE were insignificant. The results of this study suggest fast tempo background music may be used in manual materials handling tasks to increase performance without increasing perceived exertion because of its ergogenic effect on human psychology and physiology.

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Continuous versus pulsed origination and extinction and biozones

Trammer J.

Acta Geologica Polonica

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2014

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Vol. 64, no. 4

361--366

EN

The count of biozones as an approximate measure of the origination and extinction rates of index taxa (mostly species) is proposed. The mean number of extinctions of these taxa per m.y. is 1.136 (Palaeozoic mean 0.902, Mesozoic mean 1.680, Cenozoic mean 0.789). In contrast with the majority of taxa, the originations and extinctions of index taxa, as well as of other taxa belonging to biostratigraphically important systematic groups, seems to be continuous.

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Probing cellulose wettability by electron paramagnetic resonance

Ionita G., Ghica C., Ionita P.

Materials Science Poland

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2007

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Vol. 25, No. 4

1011--1017

EN

Carboxymethyl-cellulose has been labelled with a stable free radical by reaction with 4-aminotempo in the presence of a coupling agent (EEDQ). The spin-labelled cellulose is highly stable, no leaking being noticed after months at room temperature. EPR spectroscopy was used as a main tool to study the wettability of such a material. The EPR spectrum of the dry spin-labelled cellulose shows the expected anisotropy, while addition of several solvents (acetone, ethyl acetate, DCM, methanol, toluene, PEG 200) induces the splitting of the spectrum into a two component system. Thus, the EPR spectrum is composed of a mobile component superimposed onto an immobilized one. Addition of water leads to a monocomponent isotropic spectrum. These data clearly indicate the presence of two types of sites to which the spin-label is attached. Variable temperature EPR spectra showed that an increase of temperature results in an increase in the mobility of the spin-label. Deposition of plain or spin-labelled gold nanoparticles on the cellulose fibres also affects the structure of the polymeric chain, as seen by changes in the EPR spectra.