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- Annaheim, Simon, et al.
(författare)
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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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Rapport (övrigt vetenskapligt/konstnärligt)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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| 4. |
- Gavhed, Desirée, et al.
(författare)
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Mastarbete i kyla
- 1999
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Rapport (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Kristav, Per, et al.
(författare)
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Utvärdering av gästföreläsare
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I många kurser anlitas gästföreläsare. Är de värda vad de kostar? Föreläser exempelvis alltid en inbjuden professor på den professorsnivå hon/han får betalt för? Vi anlitar även gästföreläsare från näringslivet för att höja trovärdigheten och kvalitén på våra kurser, men hur väl gör de egentligen detta? Dessa frågor har väkts hos oss under de år vissa av oss kontinuerligt betalat ut arvoden för undervisning ur våra kursbudgetar.
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| 8. |
- Kuklane, Kalev, et al.
(författare)
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Evaluation of BARRIER® EasyWarm on Healthy Volunteers in Three Different Climates and Verification of the Degree of Correlation Between Tests Performed on Healthy Volunteers and in a standardized bench test
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION Anaesthesia induced hypothermia is a common serious but preventable condition associated with increased bleeding and blood transfusion, increased risk for surgical site infections and increased risk for morbid cardiac events. Active warming is effective in preventing hypothermia but there is a need for more easy to use cost-effective products making active warming available to more patients. Establishing how the environment affects skin temperature and total body heat content (TBHC) as well as the correlation between standardized bench tests and healthy volunteer skin temperature is an important aspect in developing new, more effective warming products to prevent or treat hypothermia as this means fewer healthy volunteers are needed as changes to skin temperature could be estimated based on data from bench tests. OBJECTIVES This investigation was undertaken in order to investigate the safety and efficacy of Active warming with BARRIER® EasyWarm when used in three different climate settings and using different test methods; standardized bench test T-1127 measuring temperatures on a wooden board and measuring skin and core temperature on healthy volunteers. An additional objective in this investigation was to determine the degree of correlation between these test methods. OUTCOME A statistically significant increase in TBHC is seen when comparing TBHC over time in all three climates, respectively. With this investigation design we cannot show that there is a difference in TBHC between the different climates though, i.e. the heat generated from the blanket to the subject is not significantly different in the different climates. Based on this investigation the active warming blanket managed to maintain or increase the temperature of the subjects without any adverse thermal effects. Thermal comfort and the mean thermal sensation were maintained between slightly cold and warm throughout the whole exposure length. The active self-warming blanket was well tolerated in healthy male volunteers. None of the six Adverse Events (AE) reported were serious and none of them were related to the investigational device but rather to the immobilisation or the tension of participating in the investigation. All AEs were resolved at end of test. Skin temperature reached maximally 42.2°C, and thus, it never reached the lowest pain threshold of 43°C under any conditions. Increase of core temperature over time in climate 18°C and 24°C was in average 0.1°C to 0.2°C leading to mean final core temperatures of 36.9 (SD 0.2) and 37.1 (SD 0.4) °C for 18°C and 24°C exposures, respectively.
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| 9. |
- Kuklane, Kalev, et al.
(författare)
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Interlaboratory tests on thermal foot models
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A limited Round Robin test has been carried out with different types of foot models. Eight laboratories were able to carry out tests. The foot models varied in sizes from 254 mm to 275 mm, representing boot sizes from 41 to 44. Six other laboratories were interested but were not able to carry out the tests within this study. A database has been created. New test results from other test laboratories and on other footwear can be added later on. The test series were carried out under standardised conditions in each laboratory. Ten (10) test conditions were recommended. All conditions had to be tested twice. Tests with bare foot and sock were carried out at about +20 °C and 50 % RH. The boots, a thin rubber and a winter boot, were tested at about +5 °C and 85 % RH. The conditioning was done at 20±2 °C and 35±5 % RH. Air velocity was kept low (<0.3 m/s). Wet tests included simulation of sweating by supplying water to the foot skin at a rate of 5 g/h/foot. Generally, 6 conditions were tested at most laboratories. The test series can be used as a basis for applying for a project further on that eventually would aim to suggest changes in existing European standard (EN 344) or propose a new (international) standard on footwear thermal testing. Relatively big inter-laboratory differences in measuring results were obtained. The differences were smaller for total insulation values but could be more than 30 % for local zones. Most of the differences would be explained by climatic conditions, construction of foot, measuring principle a.o. More elaborate comparative tests under different conditions and with more types of footwear need to be done. The effects of differences in model construction etc. should be analysed further. For standard use it is important to determine which zones should be included in the total insulation calculation and which zones should be reported separately, e.g. sole area. The foot construction, the conditions, measurements and calculations for wet tests should be more clearly defined.
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