| 41. |
- Holmér, Ingvar, et al.
(författare)
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Protection against cold
- 2005
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Ingår i: Textiles in Sport. - 1855739224 ; , s. 262-286
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 42. |
- Holmér, Ingvar
(författare)
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Protective clothing in hot environments
- 2006
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Ingår i: Industrial Health. - 1880-8026. ; 44:3, s. 404-413
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Forskningsöversikt (refereegranskat)abstract
- The high level of protection required by personal protective clothing (PPC) severely impedes heat exchange by sweat evaporation. As a result work associated with wearing PPC, particularly in hot environments, implies considerable physiological strain and may render workers exhausted in a short time. Recent development of algorithms for describing the heat transfer, accounting for pumping and wind effects, comprises improvement of the prediction of thermal stress. Realistic corrections can then be made to the available measures of thermal insulation and evaporative resistance of a given clothing ensemble. Currently this information is incorporated in international standards for assessment of thermal environments. Factors, such as directional radiation and wetting of layers, were studied in a recently completed EU research project. The development of advanced thermal manikins and measurement procedures should provide better measures for predictive models. As with all methods and models, the results need validation in realistic wear trials in order to prove their relevance and accuracy.
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| 43. |
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| 44. |
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| 45. |
- Holmér, Ingvar, et al.
(författare)
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Textiles for cold protection
- 2005
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Ingår i: Textiles for Protection. - 1855739224 ; , s. 360-382
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 46. |
- Holmér, Ingvar, et al.
(författare)
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Thermal stress on firefighters in extreme heat exposure
- 2006
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Ingår i: Protective clothing - towards balanced protection : : Proceedings of the 3rd European Conference on Protective Clothing (ECPC) and NOKOBETEF 8, Gdynia, 10-12 May 2006 - Proceedings of the 3rd European Conference on Protective Clothing (ECPC) and NOKOBETEF 8, Gdynia, 10-12 May 2006.
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Konferensbidrag (refereegranskat)abstract
- Five students of a rescue training school cycled at 50 W for 20 minutes at 20 °C before walking up to 30 minutes in a climatic chamber at 55 °C and 30 % relative humidity. Four different types of clothing ensembles were used differing in terms of thickness and thermal insulation value were tested on separate days. All subjects completed 28-30 minutes in light clothing, but quitted after 20-27 minutes in three firefighter ensembles due to a rectal temperature of 39.0 °C or subjective fatigue. No difference in the evolution of mean skin or rectal temperature was seen for the three turnout ensembles. Sweat production amounted to about 1000 g in the turnout gears of which less than 20 % evaporated. It was concluded that the small differences between the turnout gears in terms of design, thickness and insulation value had no effect on the resulting physiological strain for the given experimental conditions.
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| 47. |
- Holmér, Ingvar, et al.
(författare)
-
Use of Thermal Manikins in International Standards
- 2006
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Ingår i: Thermal Manikins and Modelling. - 9789623675345 ; , s. 19-24
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Konferensbidrag (refereegranskat)abstract
- The first standards based on thermal manikin measurements were developed in the 1980s. In the Nordic countries tests for thermal insulation measurements of sleeping bags and cold protective clothing were developed. Similar standards were published in Germany by DIN and in the US by ASTM. At a European level, EN 342 describes test methods and requirements for cold protective clothing based on manikin measurements. EN 511 describes a method for determining glove insulation using a thermal hand model. In 2005 ASTM published a standard for determining water vapour resistance with a sweating manikin. ISO 9920 already described in 1992 how clothing insulation could be measured with a thermal manikin. This procedure, however, is more precisely specified in ISO 15831 published in 2003. Another field of application for thermal manikins is the evaluation of thermal environments. In particular, the automobile industry has shown great interest in using manikins for vehicle climate evaluation. An international standard, ISO/DIS 14505, dealing with this particular application is on the way.
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| 48. |
- Kjellström, Tord, et al.
(författare)
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Workplace heat stress, health and productivity
- 2009
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Ingår i: Global Health Action. - 1654-9880. ; 2, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Background: Global climate change is already increasing the average temperature and direct heat exposure in many places around the world. Objectives: To assess the potential impact on occupational health and work capacity for people exposed at work to increasing heat due to climate change. Design: A brief review of basic thermal physiology mechanisms, occupational heat exposure guidelines and heat exposure changes in selected cities. Results: In countries with very hot seasons, workers are already affected by working environments hotter than that with which human physiological mechanisms can cope. To protect workers from excessive heat, a number of heat exposure indices have been developed. One that is commonly used in occupational health is the Wet Bulb Globe Temperature (WBGT). We use WBGT to illustrate assessing the proportion of a working hour during which a worker can sustain work and the proportion of that same working hour that (s)he needs to rest to cool the body down and maintain core body temperature below 388C. Using this proportion a ‘work capacity’ estimate was calculated for selected heat exposure levels and work intensity levels. The work capacity rapidly reduces as the WBGT exceeds 26
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| 49. |
- Kuklane, Kalev, et al.
(författare)
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Are standard tests of cold protection by footwear relevant and valid?
- 2008
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Ingår i: 7th International Meeting on Manikins and Modelling (7I3M).
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Konferensbidrag (refereegranskat)abstract
- The present international standards for safety, protective and occupational footwear EN ISO 20344 – 20347 classify footwear as cold protective by a pass/fail test where the limits are set for an allowed 10 °C temperature drop inside the footwear at a sole location during 30 minutes at a temperature gradient of about 40 °C. In a test of five footwear including a summer sandal it was shown that all could pass the test, since performance is basically determined by the sole insulation only. The standard does not discriminate between good and poor cold protective footwear and should be replaced by a more relevant and valid test, for example with a heated foot model.
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| 50. |
- Kuklane, Kalev, et al.
(författare)
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Calculation of Clothing Insulation by Serial and Parallel Methods: Effects on Clothing Choice by IREQ and Thermal Responses in the Cold
- 2007
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Ingår i: International Journal of Occupational Safety and Ergonomics. - : Informa UK Limited. - 2376-9130 .- 1080-3548. ; 13:2, s. 103-116
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Tidskriftsartikel (refereegranskat)abstract
- Cold protective clothing was studied in 2 European Union projects. The objectives were (a) to examine different insulation calculation methods as measured on a manikin (serial or parallel), for the prediction of cold stress (IREQ); (b) to consider the effects of cold protective clothing on metabolic rate; (c) to evaluate the movement and wind correction of clothing insulation values. Tests were carried out on 8 subjects. The results showed the possibility of incorporating the effect of increases in metabolic rate values due to thick cold protective clothing into the IREQ model. Using the higher thermal insulation value from the serial method in the IREQ prediction, would lead to unacceptable cooling of the users. Thus, only the parallel insulation calculation method in EN 342:2004 should be used. The wind and motion correction equation (No. 2) gave realistic values for total resultant insulation; dynamic testing according to EN 342:2004 may be omitted.
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