| 1. |
- Arias, Silvia, et al.
(författare)
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An experiment on ascending evacuation on a long, stationary escalator
- 2016
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Ingår i: Interflam 2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ascending evacuation is becoming more relevant with underground stations reaching increasing depths. Therefore there is need for better understanding of the effects of physical exertion during evacuation. An experiment was conducted in a 61 m long, stationary escalator in Stockholm (Sweden) in order to obtain data on walking speeds, resting and behavior, which consisted on measuring the walking speed and gathering data about the perceived exertion of test participants walking up the escalator. The walking speeds of 29 single individuals and a group of 21 individuals were obtained. The results showed that people decrease their walking speed with the height, and some of them need to take breaks along the climb. No clear influence of background participants’ variables was found on the results. In the group experiment, the slower people had an impact on the walking speed of others due to the reduced space between them at the beginning of the climb. However, the slower participants gradually move to the right hand of the escalator to allow overtaking on the left hand side, and the faster ones could move at their preferred speed. This behavior is similar that observed during regular use of escalators.
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| 2. |
- Gao, Chuansi, et al.
(författare)
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Whole body heat balance and local insulation required to prevent extremity cooling in extremely cold environments
- 2016
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Ingår i: 6th International Conference on the Physiology and Pharmacology of Temperature Regulation. ; , s. 165-165
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Konferensbidrag (refereegranskat)abstract
- IntroductionLocal cooling in winter conditions is a sensitive and early warning of whole body cooling. Previous studies showed that the equilibrium temperature for the 5th finger is strongly affected by both temperature and insulation. The international standard ISO 11079 is used to calculate clothing insulation required for the whole body based on heat balance equations. However, it does not provide possibility to determine required insulation for local protection. The European standard EN 511 has provided a simple example of the thermal insulation level required as a function of ambient air temperature at a wind speed below 0.5 m/s. The objective of this study was to investigate the relationship between glove insulation and finger temperature in an extremely cold condition.MethodsNine subjects participated in a climatic chamber (Ta -30.6 °C, Va 0.4 m/s). Hestra wind stopper fleece fabric gloves and thicker cross country ski mittens (727 g/m2) with micro fleece lining were used for four and five subjects, respectively. Cold protective clothing (Icl=1.89 clo, standard total insulation: 2.26 clo) was used for subjects walking at 232.8 W/m2 to provide whole body thermal comfort according to ASTM F2732. Results and conclusionsThe rectal temperature was relatively stable (37.4 - 37.7 °C) during walking (90 min). The mean little finger temperature reduced to 7.9 (SD 1.4) °C when wearing Hestra wind stopper fleece fabric gloves (0.95 clo), whereas the finger temperature reached 17.8 (1.2) °C when wearing thicker ski mittens (1.46 clo). The insulation of gloves is required to be approximately about the standard total insulation of the ensemble (2.26 clo) to maintain thermal equilibrium of the finger (33 °C). The relationship (Iglove = 0.0522 * Tfinger + 0.5347) between finger temperature (°C) and glove insulation (clo) is established to estimate glove insulation required in this extremely cold environment.
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| 3. |
- Halder, Amitava, et al.
(författare)
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Estimation of vertical displacement during ascending evacuation
- 2016
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Ingår i: Proceedings of the Pedestrian and Evacuation Dynamics 2016.. ; , s. 145-150
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Konferensbidrag (refereegranskat)abstract
- This paper describes an ascending evacuation model based on physical work capacity, when exhaustion may play a key role during evacuation. The experiment was carried out on a stair machine (StairMaster, SM5, USA) which involved 13 male and 12 female subjects. Individual climbing speeds at 50 and 70 % of their maximal aerobic capacity (% VO2max) level (L1 and L2) were selected for 3 minutes, and 90 %, the last level (L3) was up to 5 minutes or until exhaustion for the model development on the first 19 subjects. The model was then validated on the last 6 subjects with intended exercise levels at their 60, 75 and 90 % of their maximal aerobic capacity corresponding up to 120, 15 and 5 minutes of continuous work, respectively. The maximum vertical displacement (hvert in m/min) can be calculated according to:hvert = -21.7727+0.4024*VO2max+0.2658*% VO2max.
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| 4. |
- Kuklane, Kalev, et al.
(författare)
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A model to estimate vertical speed of ascending evacuation from maximal work capacity data
- 2016
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Ingår i: Safety Science. - : Elsevier BV. - 0925-7535. ; 89, s. 369-378
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the development of an ascending evacuation model based on physical work capacity of a selected sample. The model is based on the combination of several field experiments, existing databases and pre-tests that were combined to define initial test conditions in the laboratory environment on a step machine. Maximal oxygen consumption (VO2max) of 13 male and 12 female subjects (data was pooled), was measured, and they climbed at 3 step rates specified according to individual percentage of their maximal aerobic capacity %VO2max) levels. The first nineteen subjects were used for model development and the last six for validation. The paper gives an overview on the collected laboratory data and puts it into relation with the field data from both oxygen consumption and heart rate perspective. The maximum vertical displacement (hvert in m/min) can be calculated according to: hvert = −21.7727 + 0.4024 ∗ VO2max + 0.2658 ∗ %VO2max. The discussion covers limitations and possibilities of the model and suggests the literature and databases that form the basis for practical use of the prediction model. Paper defines the needs for future work and possible information sources to improve the model.
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