| 1. |
- Bröde, Peter, et al.
(författare)
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Heat transfer through protective clothing under symmetric and asymmetric long wave thermal radiation
- 2008
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Ingår i: Zeitschrift für Arbeitswissenschaft. - 0340-2444. ; 62:4, s. 267-276
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Tidskriftsartikel (refereegranskat)abstract
- This report considers results of an ED funded research on thermal properties ofprotective clothing and their use in the assessment of the thermal strain at work. In order to study the effects of the asymmetry oflong wave thermal radiation on the heat transfer through protective clothing, the heat loss under all-side and unilaterally applied radiation with the same incident radiant power of 279 W/m2 was measured with a thermal manikin and compared to a reference condition where mean radiant temperature was equal to air temperature. With exposure to radiation a lowered heat loss, i.e. heat gain for the whole covered body area was observed, which did not depend on radiant asymmetry for the dry as well as for the combined dry and evaporative heat loss, and which was attenuated when wearing a more insulating underwear. However, under one-sided radiation a more inhomogeneous spatial distribution occurred with higher heat gains and higher surface temperatures at the irradiated body parts. Practical Relevance The direction ofthermal radiation in the horizontal plane may be neglected when assessing the physiological heat strain in protective clothing by heat budget models. In contrast to this, it may be advisable to consider radiant asymmetries with respect to thermal comfort with low intensity radiation, and the most intense radiant source when assessing the risk of skin burns.
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| 2. |
- Bögglid, Henrik, et al.
(författare)
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Meta-analyse epidemiologischer literatur über schicharbeit und herzerkrankungen.
- 2000
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Ingår i: Zeitschrift für Arbeitswissenschaft.. - 0340-2444. ; 54:3/4, s. 330-334
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Tidskriftsartikel (refereegranskat)abstract
- Shift work has been associated with a higher risk of heart disease. The epidemiological literature is heterogeneous with some studies finding risks for shift workers twice as high as for day workers, while other studies do not find shift workers to be at a higher risk of heart disease. We have examined the literature, using a meta analytic approach to give both a more precise estimate of the risk and to explore reasons for the apparent heterogeneity. The analysis suggests that among the longitudinal studies using individual exposure classification at least two different study populations existed based on statistical testing, one finding an increased risk of heart disease with a meta risk estimate of 1.31 (95% confidence interval (CI): 1.17-1.45), the other finding no excess risk with an estimate of 0.96 (95% CI: 0.85-1.08). Study characteristics including publication year, geographic area, exposure estimation, outcome, follow up period, confounding control or overall quality of study did not explain the heterogeneity. In conclusion shift work seems in some instances, not explained by study characteristics, to raise the risk of heart disease.
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| 4. |
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| 5. |
- Rohmert, W., et al.
(författare)
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Investigations of the Maximal Endurance Time and Recovery Period for Static Muscle Work in Different Postures
- 1988
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Ingår i: Zeitschrift für Arbeitswissenschaft. - 0340-2444. ; 42:2, s. 113-115
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Tidskriftsartikel (refereegranskat)abstract
- With two different postures, USP (Upright Standing Posture) and BTP (Bent/Turned Trunk Posture) maximal force, maximal endurance time, and the necessary recovery period were ascertained using four subjects. The theoretical endurance time (TmaxRo) was calculated and compared with the empirically measured endurance time (Tmaxemp). The slight difference between empirical and calculated data for USP results from neglecting tissue forces and using idealized biomechanical models during the calculation of muscle forces. The longer empirical endurance time for BTP compared with the theoretical value probably results from the use of a number of muscles, in the back, especially those working in parallel. The models used do not correspond totally with the actual conditions, but are simplified. It is necessary to use a correction factor for calculating endurance time and recovery period for BTP.
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