| 21. |
- Gao, Chuansi, et al.
(author)
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Thermoregulatory manikins are desirable for evaluations of intelligent clothing and smart textiles
- 2010
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In: 8I3M : Eighth International Meeting for Manikins and Modeling : Victoria, BC, Canada, August 22-26, 2010 - Eighth International Meeting for Manikins and Modeling : Victoria, BC, Canada, August 22-26, 2010.
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Conference paper (peer-reviewed)abstract
- Thermal manikins have been used to measure thermal properties of clothing. The use of thermal manikins has made a step forward in terms of quantifying thermal properties of clothing in a 3-D manner compared with the use of hotplates for material testing. The effects of clothing properties measured on the thermal manikins under steady state (constant manikin surface temperature and constant environmental condition) have usually to be validated by human subject tests. The thermal insulation and evaporative resistance values measured in the constant conditions are also used in modeling to calculate heat balance, predict human thermal physiological responses, and thermal comfort. However, in many real life situations, clothing properties (e.g. moisture transfer), in particular the clothing properties with smart materials, e.g. phase change materials (PCMs), environmental conditions, sweating rate, skin temperatures are neither constant nor uniform. These make mathematical modeling complicated to take into account various transient, non-uniform conditions, and changeable properties of smart clothing which is becoming increasingly popular (Tang and Stylios 2006). Moreover, skin and core temperatures rather than heat loss or storage are commonly used to evaluate thermal comfort, define hypothermia and hyperthermia and evaluate heat strain. Therefore, the direct prediction of thermophysiological responses (skin and core temperatures) based on manikin measurements are valid (Psikuta and Rossi 2009), and could be considered another step forward towards direct evaluation of human-clothing-thermal environment interactions. In the case of measuring a personal cooling system, current standard specifies the measurement of the average heat removal rate from a sweating heated manikin (ASTM F2371-10). This heat removal rate is not constant for the PCMs. The objective of this study was to investigate the gap between the measured heat removal rate of smart clothing with PCMs obtained on a thermal manikin in a stable state, and clothing effects on local human skin and on core temperature, to compare the difference of the results obtained from both methods, and to highlight the need for developing intelligent thermoregulatory manikins.
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| 22. |
- Gao, Chuansi, et al.
(author)
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Validation of standard ASTM F2732 and comparison with ISO 11079 with respect to comfort temperature ratings for cold protective clothing
- 2015
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In: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 46:Online 17 July 2014, s. 44-53
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Journal article (peer-reviewed)abstract
- American standard ASTM F2732 estimates the lowest environmental temperature for thermal comfort for cold weather protective clothing. International standard ISO 11079 serves the same purpose but expresses cold stress in terms of required clothing insulation for a given cold climate. The objective of this study was to validate and compare the temperature ratings using human subject tests at two levels of metabolic rates (2 and 4 MET corresponding to 116.4 and 232.8 W/m(2)). Nine young and healthy male subjects participated in the cold exposure at 3.4 and -30.6 °C. The results showed that both standards predict similar temperature ratings for an intrinsic clothing insulation of 1.89 clo and for 2 MET activity. The predicted temperature rating for 2 MET activity is consistent with test subjects' thermophysiological responses, perceived thermal sensation and thermal comfort. For 4 MET activity, however, the whole body responses were on the cold side, particularly the responses of the extremities. ASTM F2732 is also limited due to its omission and simplification of three climatic variables (air velocity, radiant temperature and relative humidity) and exposure time in the cold which are of practical importance.
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| 23. |
- Gudmundsson, Anders, et al.
(author)
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Dust in Buildings - A Method for Identifying Particle Sources
- 2005
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In: Environmental ergonomics XI : proceedings of the 11th International Conference, 22-26 May, 2005, Ystad, Sweden - proceedings of the 11th International Conference, 22-26 May, 2005, Ystad, Sweden. - 9163170620 ; , s. 507-510
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Conference paper (peer-reviewed)
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| 24. |
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| 25. |
- Holmér, Ingvar, et al.
(author)
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Breath Air Flow Rates During Treadmill Walking Using Filter Respirators
- 2006
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In: 13th International Conference of Respiratory Protection.
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Conference paper (other academic/artistic)abstract
- Respiratory minute volumes and instantaneous breath flow rates were measured in 8 subjects during treadmill work using (a) a particle filter respirator(Sundstroem SR200) and (b) a control breathing mask (Metamax I, Cortex). Work comprised five consecutive bouts of walking at 5 km/h with an increase in elevation of the treadmill by 5 % every 5 minutes. Minute ventilationincreased in a curvilinear manner with oxygen uptake and reached 88±20 and 93±20 l/min at 5 km/h (20%) with the control mask and SR200, respectively. Peak inspiratory flow rate (PIFR), measured as the average of several breath cycles (in 30 sec), was 273±38 for Control and 300±36 for SR200 at the same work rate. During standardized speech communication, minute volumes decreased. In contrast, PIFR increased by about 100 % at low work rates and about 30 % at 5 km/h (20%) compared to no speech condition, reaching a highest value of 373±42 for Control and 407±48 for SR200. The time of the inhalation cycle was between 50-60 % of the total breath cycle in Control and 46-53 in SR200. During speech inhalation time was 14 and 19 % at the lowest work rate for Control and SR200, respectively. Corresponding values for the highest work rate were 38 and 33 % of total breath time. At the highest work rate mean inspiratory flow rate was 192±43 l/min for SR200. It was calculated that at the three highest work rates the mask air flow rate exceeded 95 l/min for more than 60 % of the inhalation time. During speech conditions this result was valid also for the two lowest work rates.
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| 26. |
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| 27. |
- Holmér, Ingvar, et al.
(author)
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Minute volumes and inspiratory flow rates during exhaustive treadmill walking using respirators
- 2007
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In: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 1475-3162. ; 51:3, s. 327-335
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Journal article (peer-reviewed)abstract
- Air flow rate through filters and face masks is one important determinant of the final protection factor of a respiratory protective device in use. Respiratory minute volumes and instantaneous breath flow rates were measured in eight subjects during treadmill work using three types of filtering respirators and one control breathing mask. Work comprised five consecutive bouts of walking at 5 km/h with an increase in elevation of the treadmill by 5% every 5 min and a final walk at 6 km/h and 22.5%. Three subjects managed to complete 5 min at the final work rate. Minute ventilation increased in a curvilinear manner with oxygen uptake and reached 88 +/- 20 and 93 +/- 20 l/min at 5 km/h (20%) with the control mask and a half mask with filter (SP), respectively. Mean peak inspiratory flow rate (PIEFR) was 273 +/- 39 for Control and 300 +/- 36 for SP at the same work rate. Two power assisted, positive pressure filter respirators (SA and SE) produced higher mask minute volumes at any given work rate compared to respiratory minute volumes in control and SP. PIFR in SA and SE were equal to or lesser than SP. During standardized speech communication, minute volumes decreased. In contrast, PIFR increased by about 100% at low work rates and about 30% at 5 km/h (20%) compared to no speech condition, reaching a highest value of 414 +/- 46 l/min for SE. Filter testing is made at a constant flow rate of 95 l/min, a condition that eventually needs to be reconsidered in order to ensure a relevant and valid function test.
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| 28. |
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