| 1. |
- Abele, Iveta, et al.
(författare)
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Evaluation of thermal resistance of the military sleeping bags
- 2015
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Ingår i: Advanced Materials Research. - 1022-6680. ; 1117, s. 299-302
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Tidskriftsartikel (refereegranskat)abstract
- Military sleeping bags are envisaged for intensive use during military actions. They have extra properties that provide protection for military staff. In cold climatic conditions when sleeping bags are used for rest soldiers’s combat ability and survival depends on the thermal insulation properties of material technical resources (gear) and clothing. Aim of the research is to establish the extreme temperature of military sleeping bags and military uniforms complete sets, to find the optimal set and define conformity to NATO AECTP-230 “Climatic conditions” cold climate categories C0 – C1.
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| 2. |
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| 3. |
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| 4. |
- Alametsä, Jarmo, et al.
(författare)
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Age‐related circulatory responses to whole body cooling: observations by heart rate variability
- 2015
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Ingår i: Finnish Journal of eHealth and eWelfare. - 1798-0798. ; 7:2-3, s. 57-64
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Tidskriftsartikel (refereegranskat)abstract
- The purpose was to study potential age ‐ related changes in the circulatory system via heart rate variability (HRV) by gradually lowering ambient temperature (0.2°C/min) from thermoneutral (32 C°) towards cold (18 C°). ECG was recorded from a young (31 years) and from an older subject (78 years), both males. During the tests, brachium blood pressure (BP) was recorded. During the cooling, BP increased in both subjects (young from 95/69 to 132/75 mmHg, old from 125/68 to 176/101 mmHg), the latter exhibiting a prominent rise in diastolic values after cooling. HRV parameters increased in both subjects during the cold exposure being modest in the younger subject as compared to the older one. Also, recovery from the cold in terms of HRV was faster in the younger subject. The present preliminary observations indicate that older age is coupled with altered HRV response to a mild whole‐body skin cooling.
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| 5. |
- Anttonen, Hannu, et al.
(författare)
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Thermal manikin measurements - exact or not?
- 2004
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Ingår i: International Journal of Occupational Safety and Ergonomics. - 2376-9130. ; 10:3, s. 291-300
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Tidskriftsartikel (refereegranskat)abstract
- According to the European prestandard ENV 342:1998, the thermal insulation of cold-protective clothing is measured with a thermal manikin. Systematic studies on the reproducibility of the values, measured with different types of clothing on the commonly used standing and walking manikins, have not been reported in the literature. Over 300 measurements were done in 8 different European laboratories. The reproducibility of the thermal insulation test results was good. The coefficient of variation was lower than 8%. The measured clothing should fit the manikin precisely, because poorly fitting clothing gave an error in the results. The correlation between parallel and serial insulation values was excellent and parallel values were about 20% lower than serial ones. The influence of ambient conditions was critical only in the case of air velocity. The reproducibility of thermal insulation test results in a single laboratory was good, and the variation was lower than 3%.
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| 6. |
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| 7. |
- Bröde, Peter, et al.
(författare)
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Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability
- 2010
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Ingår i: International Journal of Occupational Safety and Ergonomics. - 2376-9130. ; 16:2, s. 231-244
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Tidskriftsartikel (refereegranskat)abstract
- The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considered. Garments with different outer materials and colours and additionally an aluminised reflective suit were combined with different number and types of dry and pre-wetted underwear layers. Under radiant stress, whole body heat loss decreased, i.e., heat gain occurred compared to the reference. This heat gain increased with radiation intensity, and decreased with air velocity and clothing insulation. Except for the reflective outer layer that showed only minimal heat gain over the whole range of radiation intensities, the influence of the outer garments’ material and colour was small with dry clothing. Wetting the underclothing for simulating sweat accumulation, however, caused differing effects with higher heat gain in less permeable garments.
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| 8. |
- Bröde, Peter, et al.
(författare)
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Heat transfer through protective clothing under symmetric and asymmetric long wave thermal radiation
- 2008
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Ingår i: Zeitschrift für Arbeitswissenschaft. - 0340-2444. ; 62:4, s. 267-276
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Tidskriftsartikel (refereegranskat)abstract
- This report considers results of an ED funded research on thermal properties ofprotective clothing and their use in the assessment of the thermal strain at work. In order to study the effects of the asymmetry oflong wave thermal radiation on the heat transfer through protective clothing, the heat loss under all-side and unilaterally applied radiation with the same incident radiant power of 279 W/m2 was measured with a thermal manikin and compared to a reference condition where mean radiant temperature was equal to air temperature. With exposure to radiation a lowered heat loss, i.e. heat gain for the whole covered body area was observed, which did not depend on radiant asymmetry for the dry as well as for the combined dry and evaporative heat loss, and which was attenuated when wearing a more insulating underwear. However, under one-sided radiation a more inhomogeneous spatial distribution occurred with higher heat gains and higher surface temperatures at the irradiated body parts. Practical Relevance The direction ofthermal radiation in the horizontal plane may be neglected when assessing the physiological heat strain in protective clothing by heat budget models. In contrast to this, it may be advisable to consider radiant asymmetries with respect to thermal comfort with low intensity radiation, and the most intense radiant source when assessing the risk of skin burns.
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| 9. |
- Bröde, Peter, et al.
(författare)
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Non-evaporative effects of a wet mid layer on heat transfer through protective clothing
- 2008
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 104:2, s. 341-349
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Tidskriftsartikel (refereegranskat)abstract
- In order to assess the non-evaporative components of the reduced thermal insulation of wet clothing, experiments were performed with a manikin and with human subjects in which two layers of underwear separated by an impermeable barrier were worn under an impermeable overgarment at 20 °C, 80% RH and 0.5 ms-1 air velocity. By comparing manikin measurements with dry and wetted mid underwear layer, the increase in heat loss caused by a wet layer kept away from the skin was determined, which turned out to be small (5-6 Wm-2), irrespective of the inner underwear layer being dry or wetted, and was only one third of the evaporative heat loss calculated from weight change, i.e. evaporative cooling efficiency was far below unity. In the experiments with 8 males, each subject participated in two sessions with the mid underwear layer either dry or wetted, where they stood still for the first 30 minutes and then performed treadmill work for 60 minutes. Reduced heat strain due to lower insulation with the wetted mid layer was observed with decreased microclimate and skin temperatures, lowered sweat loss and cardiac strain. Accordingly, total clothing insulation calculated over the walking period from heat balance equations was reduced by 0.02 m2 °C W-1 (16%), while for the standing period the same decrease in insulation, representing 9% reduction only showed up after allowing for the lower evaporative cooling efficiency in the calculations. As evaporation to the environment and inside the clothing was restricted, the observed small alterations may be attributed to the wet mid layer’s increased conductivity, which, however, appears to be of minor importance compared to the evaporative effects in the assessment of the thermal properties of wet clothing.
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| 10. |
- Bröde, Peter, et al.
(författare)
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Thermische Beanspruchung in Schutzkleidung
- 2010
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Ingår i: Technische Überwachung. ; 51:6, s. 14-18
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in German Grundlegende Daten zur Beurteilung der thermischen Beanspruchung während der Arbeit in Schutzkleidung wurden im europäischen Verbundprojekt THERMPROTECT (EU Contract-No. G6RD-CT-2002-00846) mit Untersuchungen des durch die Kleidung erhöhten Energieumsatzes und des Transports von Wärme und Feuchte unter Kältebelastung sowie bei Einwirkung von Wärmestrahlung erhoben. Der Eingang der hier dargestellten Resultate in international standardisierte Bewertungsverfahren soll zur Vermeidung thermophysiologischer Überbeanspruchungen beitragen.
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