| 1. |
- Annaheim, Simon, et al.
(author)
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Final report of Working Group 4: Ergonomics of thermal effects. A COST Action TU1101 / HOPE collaboration
- 2015
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Reports (other academic/artistic)abstract
- The thermal effects related to wearing a bicycle helmet are complex and different studies have investigated single parts of this topic. A literature review was produced and published (Bogerd et al., 2015) summarizing the different findings to give a complete overview on this topic as well as to suggest new perspectives. Headgear increases head insulation and therefore is mainly problematic under warm conditions, which is the focus of that review. Helmets do not affect physiological parameters other than the local skin temperature and sweat rate. However, the head is among the most sensitive body parts related to thermal comfort, thereby directly affecting the willingness to wear headgear. Several methods have been used to study thermal aspects of headgear, which could be categorized as (i) numerical, (ii) biophysical, (iii) combined numerical and biophysical, and (iv) user trials. The application of these methods established that heat transfer mainly takes place through radiation and convection. Headgear parameters relevant to these heat transfer pathways are reviewed and suggestions are provided for improving existing headgear concepts and developing new concepts, ultimately leading to more accepted headgear. The report of working group 4 (WG4) provides information about activities undertaken during the COST Action TU1101 “Towards safer bicycling through optimization of bicycle helmets and usage” to better understand the ergonomics of thermal aspects and to work towards the tasks defined in the memorandum of understanding (COST Secretariat, 2011). Primary Task 5: Development of guidelines for thermally-optimized helmet designs Secondary Task 3: Inform impact studies on which kinds of ventilation structures are useful and which are unnecessary Secondary Task 7: Review of physiological and comfort effect of wearing bicycle helmets All the chapters listed below include important aspects contributing to the primary task 5. Modelling and simulation tools (Chapter II) are becoming more and more important in research and development of new bicycle helmets but also in the development of guidelines, directives and norms. An example for the industrial application of models is given in Chapter III. The investigation of different forms of helmet coverings provides important information about the future direction for the development of helmet designs. Completely new helmet designs and the respective thermal properties are presented in Chapter IV. This chapter shows a different approach for finding new concepts of helmet designs. In Chapter V, new project initiatives are introduced to improve thermal aspects of helmets but also to include information and communication techniques (ICT) into helmets. Finally, the tasks of WG4 are summarized in Chapter VI, conclusions are drawn and an outlook is provided regarding the future development of helmets to comply with the requests of two-wheel commuters (including e-bikes, segway and others).
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| 2. |
- Halder, Amitava, et al.
(author)
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Predicted Heat Strain (PHS) model and the sweat loss in an extremely hot climate
- 2019
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Conference paper (peer-reviewed)abstract
- Introduction: The aim was to study if the evaporative water loss can be predicted enough accurately for hydration recommendations by ISO 7933 – Predicted Heat Strain (PHS) model during a student laboratory exercise in an extremely hot environment.Method: Twelve young healthy students (8 males and 4 females), unacclimatized to heat, were exposed in a climatic chamber at 50˚C, 30% relative humidity and 0.4 m·s-1 air velocity for 45 minutes. They had a mean (SD) age of 25.1 (2.6) years, height 175.6 (6.9) cm, weight 72.3 (11.0) kg, VO2max 54.9 (6.5) mL·min-1·kg-1, and HRmax 194 (6) bpm. The men and women performed bicycling for 6-minutes at workloads of 150 and 100 Watts (W), when the metabolic rates (M) calculated found 363 and 290 W·m-2, respectively. Moreover, the students did step test at 60 steps·min-1 for 5-minutes with estimated M being 215 W·m-2. They were standing most of the time (34 min) (M = 80 W·m-2). Time weighted average M for males and females were 133 and 123 W·m-2, respectively, for the whole exposure duration. Clothing insulation, Icl = 0.4 clo and moisture permeability index, im = 0.42 were input to PHS model simulation. The actual water loss by evaporation was determined by subject’s dressed body weight difference before and after exposure.Results: The actual mean (SD) total water evaporated was 461.3 (176.7) g. The predicted total water loss was 427.4 (39.2) g by the PHS model. There was no significant (p = .514) difference between the actual and the predicted water loss. However, the original estimation of evaporative sweat was found only 270.1 g.Conclusions: These results suggest that it is challenging to predict the water loss in continuous extreme heat exposure at 50˚C using ISO 7933 – PHS model. It should be used cautiously to predict the dehydration, and plan for drinking in extremely hot climates.
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| 3. |
- Shinar, David, et al.
(author)
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Reporting bicycle accidents to police in the COST TU1101 survey data base: Cross-country comparisons and associated factors
- 2016
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In: ; , s. 9-9
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Conference paper (peer-reviewed)abstract
- Police crash reports are often the main source for official data in many countries. However, police sampling and data are known to be subject to bias, making the countermeasures adopted according to them possibly inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. The following paper utilizes data collected in the COST TU1101 action. The data came from an online survey that included questions related with bicyclists' attitudes, accidents, and pattern of use of helmets. An average of only 10% of all crashes were reported to the police (minimum of 0.0% Israel and 3.37% Greece to a maximum of a 30% of Germany). Some factors associated with the reporting level were: type of crash, type of vehicle and injury severity. Finally, no relation was found between the likelihood of reporting and the cyclist's gender, age, use of helmet, and type of bicycle. The significant under-reporting justifies the use of survey data for assessment of bicycling crash patterns as they relate to crash risk issues such as location, cyclists' characteristics, and use of helmet and strategic approaches to bicycle crash prevention and injury reduction, which are discussed in the paper.
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| 4. |
- Shinar, David, et al.
(author)
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Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors
- 2018
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In: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575. ; 110, s. 177-186
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Journal article (peer-reviewed)abstract
- Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling.This study utilized data collected in the COST TU1101 action “Towards safer bicycling through optimization of bicycle helmets and usage”. The data came from an online survey that included questions related to bicyclists' attitudes, behaviour, cycling habits, accidents, and patterns of use of helmets. The survey was filled by 8655 bicyclists from 30 different countries. After applying various exclusion factors, 7015 questionnaires filled by adult cyclists from 17 countries, each with at least 100 valid responses, remained in our sample.The results showed that across all countries, an average of only 10% of all crashes were reported to the police, with a wide range among countries: from a minimum of 0.0% (Israel) and 2.6% (Croatia) to a maximum of a 35.0% (Germany). Some factors associated with the reporting levels were type of crash, type of vehicle involved, and injury severity. No relation was found between the likelihood of reporting and the cyclist's gender, age, educational level, marital status, being a parent, use of helmet, and type of bicycle.The significant under-reporting – including injury crashes that do not lead to hospitalization – justifies the use of self-report survey data for assessment of bicycling crash patterns as they relate to (1) crash risk issues such as location, infrastructure, cyclists' characteristics, and use of helmet and (2) strategic approaches to bicycle crash prevention and injury reduction.
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