| 1. |
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| 2. |
- Holmér, Ingvar, et al.
(författare)
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Respiration and air flow pattern and airflow patterns during incremental exercise with respirators
- 2005
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Ingår i: 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. - 1650-9773. - 9163170620 ; , s. 455-458
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Konferensbidrag (refereegranskat)
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| 3. |
- Kuklane, Kalev, et al.
(författare)
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Calculation of clothing insulation by serial and parallel model, their effect on clothing choice by IREQ and thermal responses in the cold
- 2005
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Ingår i: 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. - 1650-9773. - 9163170620 ; , s. 445-448
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Konferensbidrag (refereegranskat)
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| 4. |
- Abeysekera, John, et al.
(författare)
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The identification of factors in the systematic evaluation of slip prevention on icy surfaces
- 2001
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 28:5, s. 303-313
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Tidskriftsartikel (refereegranskat)abstract
- Slips and falls on icy roads often result in fractures or sprains and is a major problem in Nordic countries. Walking trials by 25 subjects wearing four types of winter shoes on five different icy walking surfaces provided subjective and objective measures of tendency to slip and number of slips, respectively. Since friction is a major determinant of a slip, the influence of material spread on icy surfaces, the surface temperatures and the shoe soling characteristics versus the Coefficient of Friction (COF) of the shoes were measured. Sand and gravel on icy roads had positive effects on improving COF. The study revealed that the aetiology of slips and falls is multi-faceted and attempts to solve the problem must adopt a systems approach. Perception of risk, aging, training, experience and postural balance are other factors to be considered in preventing slips and falls. Future research should concentrate on the degree of impact of each factor to the aetiology of slips and falls, which can help to decide priority action in preventing slips and falls.
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| 5. |
- Adams, Nicholas, et al.
(författare)
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El Niño Southern Oscillation, monsoon anomaly, and childhood diarrheal disease morbidity in Nepal
- 2022
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Ingår i: PNAS Nexus. - : Oxford University Press (OUP). - 2752-6542. ; 1:2
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is adversely impacting the burden of diarrheal diseases. Despite significant reduction in global prevalence, diarrheal disease remains a leading cause of morbidity and mortality among young children in low- and middle-income countries. Previous studies have shown that diarrheal disease is associated with meteorological conditions but the role of large-scale climate phenomena such as El Niño-Southern Oscillation (ENSO) and monsoon anomaly is less understood. We obtained 13 years (2002–2014) of diarrheal disease data from Nepal and investigated how the disease rate is associated with phases of ENSO (El Niño, La Niña, vs. ENSO neutral) monsoon rainfall anomaly (below normal, above normal, vs. normal), and changes in timing of monsoon onset, and withdrawal (early, late, vs. normal). Monsoon season was associated with a 21% increase in diarrheal disease rates (Incident Rate Ratios [IRR]: 1.21; 95% CI: 1.16–1.27). El Niño was associated with an 8% reduction in risk while the La Niña was associated with a 32% increase in under-5 diarrheal disease rates. Likewise, higher-than-normal monsoon rainfall was associated with increased rates of diarrheal disease, with considerably higher rates observed in the mountain region (IRR 1.51, 95% CI: 1.19–1.92). Our findings suggest that under-5 diarrheal disease burden in Nepal is significantly influenced by ENSO and changes in seasonal monsoon dynamics. Since both ENSO phases and monsoon can be predicted with considerably longer lead time compared to weather, our findings will pave the way for the development of more effective early warning systems for climate sensitive infectious diseases.
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| 6. |
- Alametsä, Jarmo, et al.
(författare)
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Age-related circulatory responses to whole body cooling: observations by ballistocardiographic EMFi sensors
- 2014
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Ingår i: Proceedings of Ambience 14&10i3m : Scientific Conference for Smart and Functional Textiles, Well-Being, Thermal Comfort in Clothing, Design, Thermal Manikins and Modellin, 7-9 September 2014, Tampere, Finland - Scientific Conference for Smart and Functional Textiles, Well-Being, Thermal Comfort in Clothing, Design, Thermal Manikins and Modellin, 7-9 September 2014, Tampere, Finland. - 2342-4540. - 9789521532696 ; 1
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Konferensbidrag (refereegranskat)abstract
- The purpose was to study age related changes in circulatory system via Ballistocardiography (BCG) by utilizing Electromechanical Film (EMFi) sensors by gradually changing the ambient temperature from a thermoneutral area to cold direction. ECG and BCG were recorded from a young person (23 years) and from an older person (78 years), both males. During the tests, brachium blood pressure (BP) and pulse signals were recorded from neck and ankle (with EMFi sensor strips). Thermal camera images were taken in order to find out temperature changes in whole body and limbs. Temporal durations and amplitudes of seat BCG:s components (systolic and diastolic) as well as from pulse signals from neck and ankle were calculated. Aortic pulse wave velocity (PWV) was obtained by utilizing the time between ECG’s R wave and maximum value of the ankle pulse signal. In both persons, the ankle pulse amplitude decreased when propagating to cold direction and increased in young person when returning to warmer ambient temperature. With young and old BCG:s systolic and diastolic temporal complexes remained stable, but systolic amplitudes increased in the older person (AHI 1.02 – 2.87, AIJ 0.7 – 2.66) as well as diastolic amplitudes (old; AKL 0.47 – 2.37). In the older person, PWV increased when moving to colder side. BP increased with a young person (from 95/64 to 132/75 mmHg), and with older person (from 125/68 to 176/101 mmHg) having a prominent rise in diastolic values during the cooling. The neck pulse wave amplitude AOP rise was modest with the younger person and had variation with the older person. Older person had also more intensive shivering compared to younger one. With the older person, the limbs stayed cold in thermal images when returning from cold to thermoneutral area. The present preliminary observations indicated clear age-related differences in the circulatory response to a mild whole-body thermal challenge.
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| 7. |
- 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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| 8. |
- An, Dong, et al.
(författare)
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Extreme precipitation patterns in the Asia-Pacific region and its correlation with El Niño-Southern Oscillation (ENSO)
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- In the Asia-Pacific region (APR), extreme precipitation is one of the most critical climate stressors, affecting 60% of the population and adding pressure to governance, economic, environmental, and public health challenges. In this study, we analyzed extreme precipitation spatiotemporal trends in APR using 11 different indices and revealed the dominant factors governing precipitation amount by attributing its variability to precipitation frequency and intensity. We further investigated how these extreme precipitation indices are influenced by El Niño-Southern Oscillation (ENSO) at a seasonal scale. The analysis covered 465 ERA5 (the fifth-generation atmospheric reanalysis of the European Center for Medium-Range Weather Forecasts) study locations over eight countries and regions during 1990-2019. Results revealed a general decrease indicated by the extreme precipitation indices (e.g., the annual total amount of wet-day precipitation, average intensity of wet-day precipitation), particularly in central-eastern China, Bangladesh, eastern India, Peninsular Malaysia and Indonesia. We observed that the seasonal variability of the amount of wet-day precipitation in most locations in China and India are dominated by precipitation intensity in June-August (JJA), and by precipitation frequency in December-February (DJF). Locations in Malaysia and Indonesia are mostly dominated by precipitation intensity in March-May (MAM) and DJF. During ENSO positive phase, significant negative anomalies in seasonal precipitation indices (amount of wet-day precipitation, number of wet days and intensity of wet-day precipitation) were observed in Indonesia, while opposite results were observed for ENSO negative phase. These findings revealing patterns and drivers for extreme precipitation in APR may inform climate change adaptation and disaster risk reduction strategies in the study region.
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| 9. |
- Andhikaputra, Gerry, et al.
(författare)
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The impact of temperature and precipitation on all-infectious-, bacterial-, and viral-diarrheal disease in Taiwan
- 2023
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 1879-1026 .- 0048-9697. ; 862
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The ongoing climate change will elevate the incidence of diarrheal in 2030-2050 in Asia, including Taiwan. This study investigated associations between meteorological factors (temperature, precipitation) and burden of age-cause-specific diarrheal diseases in six regions of Taiwan using 13 years of (2004-2016) population-based data.METHODS: Weekly cause-specific diarrheal and meteorological data were obtained from 2004 to 2016. We used distributed lag non-linear model to assess age (under five, all age) and cause-specific (viral, bacterial) diarrheal disease burden associated with extreme high (99th percentile) and low (5th percentile) of climate variables up to lag 8 weeks in six regions of Taiwan. Random-effects meta-analysis was used to pool these region-specific estimates.RESULTS: Extreme low temperature (15.30 °C) was associated with risks of all-infectious and viral diarrhea, with the highest risk for all-infectious diarrheal found at lag 8 weeks among all age [Relative Risk (RR): 1.44; 95 % Confidence Interval (95 % CI): 1.24-1.67]. The highest risk of viral diarrheal infection was observed at lag 2 weeks regardless the age. Extreme high temperature (30.18 °C) was associated with risk of bacterial diarrheal among all age (RR: 1.07; 95 % CI: 1.02-1.13) at lag 8 weeks. Likewise, extreme high precipitation (290 mm) was associated with all infectious diarrheal, with the highest risk observed for bacterial diarrheal among population under five years (RR: 2.77; 95 % CI: 1.60-4.79) at lag 8 weeks. Extreme low precipitation (0 mm) was associated with viral diarrheal in all age at lag 1 week (RR: 1.08; 95 % CI: 1.01-1.15)].CONCLUSION: In Taiwan, extreme low temperature is associated with an increased burden of viral diarrheal, while extreme high temperature and precipitation elevated burden of bacterial diarrheal. This distinction in cause-specific and climate-hazard specific diarrheal disease burden underscore the importance of incorporating differences in public health preparedness measures designed to enhance community resilience against climate change.
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| 10. |
- Brimicombe, Chloe, et al.
(författare)
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A scoping review on heat indices used to measure the effects of heat on maternal and perinatal health
- 2024
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Ingår i: BMJ Public Health. - 2059-7908. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- A previous systematic review has shown associations between exposure to high temperatures and negative birth outcomes. To date, a scoping review for heat indices and their use to measure effects of heat on maternal and perinatal health has not been considered.Objectives To provide a scoping review on heat stress and indices for those interested in the epidemiology and working in extreme heat and maternal perinatal health.Methods This study is a scoping review based on a previous review guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. It identifies the main ways heat stress through different heat indices impacts maternal and perinatal health in available literature. For documents that met the inclusion criteria, we extracted 23 publications.Results We find four heat indices: heat index, apparent temperature, wet bulb globe temperature and universal thermal climate index. Exposure to elevated levels of heat stress can be associated with preterm birth. In addition, the more intense and prolonged duration of exposure to heat stress, the greater the risk of stillbirth. Negative birth outcomes can occur from change in hormonal levels (ie, cortisol), dehydration and blood flow diversion away from the placenta and fetus when suffering from heat stress. All studies demonstrate that certain socioeconomic factors influence the effect of heat on maternal and perinatal health outcomes.Conclusion We make three suggestions based on the results: (1) heat indices should be standardised across studies and explained. (2) An increased number of perinatal and maternal health outcomes explored. Finally, (3) enhanced collaboration across climate and health to improve understanding.
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| 11. |
- Bröde, Peter, et al.
(författare)
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Infrared radiation effects on heat loss measured by a thermal manikin wearing protective clothing
- 2005
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Ingår i: 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. - 1650-9773. - 9163170620 ; , s. 74-77
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Konferensbidrag (refereegranskat)
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| 12. |
- Bülow-Hübe, Helena, 1964-, et al.
(författare)
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Nuläge termisk komfort : en kunskapssammanställning
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Boverket ser ett behov av en kunskapssammanställning kring nuläget inom termisk komfort i Sverige för att ha en så bred och korrekt förståelse som möjligt för vem branschen är, vilka regler som tillämpas, var det finns kunskapscentra och vilka utvecklingsbehov som behöver stödjas för att branschen ska kunna ta större ansvar.Några faktafrågeställningar som vi författare noterat och som kan vara värda att kartlägga ytterligare:Metoder att simuleraKlimatdata för analyser och simuleringarBetydelsen av värmeöarÅtgärder för att minska värmelaster på byggnaderörbereda plats i byggnader för komfortkylaRisker med fukt och påväxt vid komfortkylaPrioriterade rum för termisk komfortUpplåtelseformers inverkan, utsatta grupper och lokala reglerVädring och fläktarPrioritera passiva åtgärderPortabel luftkylning/komfortkylaTillsyn och bygglovKrav som inte är samordnade (energi, dagsljus, buller, etc.)VarningssystemFörhoppningen är att kartläggning av termisk komfort ska bidra till kunskapsspridning om bransch, aktörer, teknik, system, konstruktion, kontroller, drift och underhåll samt forskning och utveckling.
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| 13. |
- Del Ferraro, Simona, et al.
(författare)
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A potential wearable solution for preventing heat strain in workplaces : The cooling effect and the total evaporative resistance of a ventilation jacket
- 2022
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Ingår i: Environmental Research. - : Elsevier BV. - 1096-0953 .- 0013-9351. ; 212
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Tidskriftsartikel (refereegranskat)abstract
- The increase in average seasonal temperatures has an impact in the occupational field, especially for those sectors whose work activities are performed outdoors (agricultural, road and construction sectors). Among the adaptation measures and solutions developed to counteract occupational heat strain, personal cooling garments represent a wearable technology designed to remove heat from the human body, enhancing human performance. This study aims to investigate the effectiveness and the cooling power of a specific cooling garment, i.e. a ventilation jacket, by quantifying the evaporative heat losses and the total evaporative resistance both when worn alone and in combination with a work ensemble, at three adjustments of air ventilation speed. Standardised "wet" tests in a climatic chamber were performed on a sweating manikin in isothermal conditions considering three clothing ensembles (single jacket, work ensemble and a combination of both) and three adjustments of fan velocity. Results showed a significant increase (p < 0.001) in evaporative heat loss values when the fan velocity increased, particularly within the trunk zones for all the considered clothing ensembles, showing that fans enhanced the dissipation by evaporation. The cooling power, quantified in terms of percent changes of evaporative heat loss, showed values exceeding 100% when fans were on, in respect to the condition of fans-off, for the trunk zones except for the Chest. A significant (p < 0.01) decrease (up to 42.3%) in the total evaporative resistance values of the jacket, coupled with the work ensemble, was found compared to the fans-off condition. Results confirmed and quantified the cooling effect of the ventilation jacket which enhanced the evaporative heat losses of the trunk zones, helping the body to dissipate heat and showing the potential for a heat adaptation measure to be developed.
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| 14. |
- Del Ferraro, Simona, et al.
(författare)
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Cooling garments against environmental heat conditions in occupational fields : measurements of the effect of a ventilation jacket on the total thermal insulation
- 2021
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141. ; 86
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Tidskriftsartikel (refereegranskat)abstract
- Personal cooling garments (PCGs) can represent an adaptation solution to counteract heat strain and to improve worker's health and productivity (especially for some outdoor work activities as in agriculture and in the construction industry). The cooling effect of a ventilation jacket was preliminarily investigated carrying out “dry” tests in a climatic chamber on a thermal manikin. A standardized condition with air temperature, ta = 22.4 °C, three different adjustments of the fan velocity (vf= 0, vf = 2 and vf = 4), and three different ensembles (the single jacket, a work ensemble and a combination of both) were considered. Results showed significant increases in dry heat losses (through convection) for the trunk thermal zones, higher when the fans were on, for all the ensembles considered. Percent changes greatly exceeded 100 % for the thermal zones close to the fans. The air ventilation determined significant decreases of the total thermal insulation (IT) values (up to 35 %) compared to the fans-off condition, confirming and quantifying the cooling effect of the ventilation jacket.
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| 15. |
- Del Ferraro, Simona, et al.
(författare)
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Mitigating heat effects in the workplace with a ventilation jacket : simulations of the whole-body and local human thermophysiological response with a sweating thermal manikin in a warm-dry environment
- 2024
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Ingår i: Journal of Thermal Biology. - 0306-4565. ; 119
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is increasingly affecting human well-being and will inevitably impact on occupational sectors in terms of costs, productivity, workers' health and injuries. Among the cooling garment developed to reduce heat strain, the ventilation jacket could be considered for possible use in workplaces, as it is wearable without limiting the user's mobility and autonomy. In this study, simulations with a sweating manikin are carried out to investigate the effects of a short-sleeved ventilation jacket on human thermophysiological responses in a warm-dry scenario. Simulations were performed in a climatic chamber (air temperature = 30.1 °C; air velocity = 0.29 m/s; relative humidity = 30.0 %), considering two constant levels of metabolic rate M (M 1 = 2.4 MET; M 2 = 3.2 MET), a sequence of these two (Work), and three levels of fan velocities (l f = 0; l f=2; l f=4). The results revealed a more evident impact on the mean skin temperature (T sk) compared to the rectal temperature (T re), with significant decreases (compared to fan-off) at all M levels, for T sk from the beginning and for T re from the 61 st minute. Skin temperatures of the torso zones decreased significantly (compared to fan-off) at all M levels, and a greater drop was registered for the Back. The fans at the highest level (l f=4) were significantly effective in improving whole-body and local thermal sensations when compared to fan-off, at all M levels. At the intermediate level (l f=2), the statistical significance varied with thermal zone, M and time interval considered. The results of the simulations also showed that the Lower Torso needs to be monitored at M 2 level, as the drop in skin temperature could lead to local overcooling and thermal discomfort. Simulations showed the potential effectiveness of the ventilation jacket, but human trials are needed to verify its cooling power in real working conditions.
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| 16. |
- Eggeling, Jakob, et al.
(författare)
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Spatiotemporal link between El Niño Southern Oscillation (ENSO), extreme heat, and thermal stress in the Asia-Pacific region
- 2024
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Ingår i: Scientific Reports. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is closely monitored and numerous studies reports increasing air temperature and weather extremes across the globe. As a direct consequence of the increase of global temperature, the increased heat stress is becoming a global threat to public health. While most climate change and epidemiological studies focus on air temperature to explain the increasing risks, heat strain can be predicted using comprehensive indices such as Universal Thermal Climate Index (UTCI). The Asia-Pacific region is prone to thermal stress and the high population densities in the region impose high health risk. This study evaluated the air temperature and UTCI trends between 1990 and 2019 and found significant increasing trends for air temperature for the whole region while the increases of UTCI are not as pronounced and mainly found in the northern part of the region. These results indicate that even though air temperature is increasing, the risks of heat stress when assessed using UTCI may be alleviated by other factors. The associations between El Niño Southern Oscillation (ENSO) and heat stress was evaluated on a seasonal level and the strongest regional responses were found during December-January (DJF) and March-May (MAM).
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| 17. |
- Eggeling, Jakob, et al.
(författare)
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The usability of ClimApp : A personalized thermal stress warning tool
- 2022
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Ingår i: Climate Services. - : Elsevier BV. - 2405-8807. ; 27
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Tidskriftsartikel (refereegranskat)abstract
- ClimApp was developed to assist individuals in reducing the risk of exposure to thermal stress and to supply the user with individualized advice and recommendations. The tool integrates several human thermal models and heat indices with the local weather forecast and goes on to provide users with a prediction of their thermal stress based on their activity level, clothing level, and heat acclimatization input. Despite its innovative and interactive functionality, ClimApp's utility and ease of use should be considered to increase its usability. The usability of ClimApp was evaluated over two iterations: one usability lab test (n = 10) and one field test (n = 38) where first-time users completed tasks in ClimApp related to navigation, perceived ease of use, and perceived usefulness. Activity theory guided the analysis, and a directed qualitative content analysis was applied to evaluate the usability of ClimApp. The results suggest that there is room for improvement when assessing the universal design aspects, navigation, and information complexity, yet the participants perceived the tool as useful in the situated context.
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| 18. |
- Eggeling, Jakob, et al.
(författare)
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Validating an advanced smartphone application for thermal advising in cold environments
- 2023
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Ingår i: International Journal of Biometeorology. - 1432-1254. ; 67:12, s. 1957-1964
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Tidskriftsartikel (refereegranskat)abstract
- The ClimApp smartphone application was developed to merge meteorological forecast data with personal information for individualized and improved thermal warning during heat and cold stress and for indoor comfort in buildings. For cold environments, ClimApp predicts the personal thermal stress and strain by the use of the Insulation REQuired model that combines weather and personal physiological data with additional consideration of the Wind Chill index based on the local weather forecast. In this study, we validated the individualized ClimApp index relative to measurements and compared it with the Universal Temperature Climate Index (UTCI). To this aim, 55 participants (27 females) were exposed to at least 1 h in an outdoor environment of 10 °C or below (average 1.4 °C air temperature, 74.9% relative humidity, and 4.7 m/s air velocity) inputting their activity level and clothing insulation as instructed by ClimApp. The UTCI and ClimApp indices were calculated and compared to the participants' perceived thermal sensation. The ClimApp index root mean square deviation (RMSD) was below the standard deviation of the perceived thermal sensation which indicates a valid prediction and the UTCI RMSD was higher than the standard deviation which indicates an invalid prediction. The correlation of ClimApp and UTCI to the perceived thermal sensation was statistically significant for both models.
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| 19. |
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| 20. |
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| 21. |
- Fukazawa, Takako, et al.
(författare)
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Usability of a newly developed thermal manikin of infant to assess thermal stress in various environments
- 2005
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Ingår i: 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. - 1650-9773. - 9163170620 ; , s. 618-623
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Konferensbidrag (refereegranskat)
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| 22. |
- Fung, Frederick, et al.
(författare)
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Water vapor resistance measured on sweating thermal manikin and Permetest skin model in the vertical orientation
- 2020
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Ingår i: Communications in Development and Assembling of Textitle Products. - : Sachsische Landesbibliothek, Staats- und Universitatsbibliothek Dresden. - 2701-939X. ; 1:1, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- This paper is a comparison of water vapor resistance (Ret) measured using the Permetest skin model and Tore sweating thermal manikin, i.e. 2D versus 3D methods; and to study the relationship between them. Three materials and five air gap distances were used for the measurement between these two devices, the test conditions in the climatic chambers were set up according to the ISO standard of each measurement method. Results of the correlation coefficient of three materials showed that they all had a strong increasing trend between Permetest and the sweating thermal manikin. From the regression analysis, the P-value of all three materials showed that P< 0.05 and 100% cotton R2=0.83, 50% cotton 50% polyester R2=0.91, 100% polyester R2=0.99. However, Ret resulting values from each device slowed down after 12mm air gap distance.
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| 23. |
- Gao, Chuansi, et al.
(författare)
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A systems perspective of slip and fall accidents on icy and snowy surfaces
- 2004
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Ingår i: Ergonomics. - : Informa UK Limited. - 0014-0139 .- 1366-5847. ; 47:5, s. 573-598
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Tidskriftsartikel (refereegranskat)abstract
- Current research on slips and falls has mainly focused on floors and/or contaminated floors. Although icy and snowy surfaces near melting temperature are more slippery, more important still, slip and falls on icy and snowy surfaces involve not only outdoor workers, but also pedestrians and the general public; and occur in cold regions and in the winter season in many parts of the world. However, in comparison with the size of the problem, research work done so far in this area has been limited. The objective of this paper is to present a systems perspective of slip and fall accidents, with special focus on its occurrence on icy and snowy surfaces. In order to explore the aetiology of slip and fall accidents further, and to provide the basis for prevention, the authors put forward a systems model towards the slips and falls on icy and snowy surfaces based on a review of literature and current knowledge. Various contributing factors are systematically discussed to highlight the multi-factorial nature of the problem, providing the possibility of a multi-faceted approach to reach systematic prevention. Unresolved issues related to slips and falls on ice and snow are also identified, which necessitate further research.
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| 24. |
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| 25. |
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| 26. |
- Gao, Chuansi, et al.
(författare)
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Clothing Insulation Required for Energy Efficiency (IREQee) and Thermal Comfort
- 2016
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Ingår i: Proceedings of the 11th International Meeting on Thermal Manikin and Modeling(11i3m). - 9789887766209 ; , s. 28-29
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Konferensbidrag (refereegranskat)abstract
- Thermal comfort has direction implications for energy efficiency and sustainable development. From a global perspective, about 40% of total primary energy is used in buildings, contributing to more than 30% of CO2 emissions [1]. The fact that the common practices of clothing choices have impact on energy efficiency is ignored [2-3]. This paper analyzed and proposed clothing insulation required for energy efficiency (IREQee) in order to increase indoor temperature interval and energy efficiency. In many heated/air-conditioned indoor environments, it is not unusual that occupants wear T-shirts/suits. The basic clothing insulation of these clothing ensembles is estimated to be about 0.5/1.0 clo [4]. The benefit of adding/reducing clothing insulation in heated/cooled environments, e.g. change clothing between 1.2 and 0.4 clo, is that the temperature of the whole room or building can be changed by 5.1 °C (between 20.4 and 25.5 °C) while still maintaining thermal comfort (Fig. 1) calculated according to international standard [5] and related web based tool [6], given that other parameters are the same (metabolic rate M=70 W/m2, relative humidity=50%, mean radiant temperature=air temperature, mechanic work=0, relative air velocity (m/s)=0.0052*(M-58)). As a result, the energy for heating/cooling the indoor environment is saved. The saved energy is about 10% for each degree Celsius decrease or increase in heated or air-conditioned indoor air temperature [7]. Hence, informed occupant’s clothing behavior change based on IREQee can extend the interval of comfort temperature, e.g. from 18.6 to 26.1 °C (rather than a fixed set point at 22 or 23 °C) for office work in heated and air-conditioned environments. The analysis indicates that the proposed IREQee in relation to physical work intensity can function as a low cost measure to maintain thermal comfort, save energy, and enhance sustainable development. Figure 1. Required clothing insulation for energy efficiency (IREQee) and comfortable temperature in heated or air-conditioned indoor environments in relation to physical work intensity (metabolic rate: M=70 and 100 W/m2 corresponding to office work and low physical intensity work).
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| 27. |
- Gao, Chuansi
(författare)
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Clothing modulated heat stress in the context of climate change
- 2017
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Ingår i: International Society of Biometeorology. ; , s. 66-67
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Konferensbidrag (refereegranskat)abstract
- The increase in average global temperature and higherfrequency of heat waves predicted by the majority ofmeteorological models will increase the effect of heat stresson human beings. For specifically addressing the impact ofthis environmental health risk on individuals, improvedmethods including individual factors such as clothing andmetabolic rate are needed. This presentation gives anoverview of the importance of protective clothing in relationto heat stress indices (WBGT, PHS, UTCI).Human body heat production and heat dissipation must bebalanced. The latter becomes difficult if environmental heatstress level is high. Clothing can protect against extremeheat and other hazards, but it resists also heat dissipationfrom the body to the environment. The efficacy of the aboveheat stress indices is limited due to insufficient integration ofprotective clothing and its interaction with climates. Themagnitude of evaporative heat loss hampered by clothing isnot constant in hot dry and hot humid environments. Thus,the heat stress modulated by clothing and its interaction withclimate should be integrated into any comprehensive heatstress assessment in the context of climate change.Current WBGT index assumes ordinary one-layer workclothing. Clothing adjustment factor is being introduced toWBGT index. However, a constant clothing adjustmentfactor may not work for both hot dry and hot humid climates.67PHS index does not apply to clothing insulation higher than1.0 clo. UTCI is limited in its assessment to a fixed moderatemetabolic rate and typical clothing for urban populations. Onthe warm side at air temperature about 32 to 40°C, the basicleisure clothing insulation is only modelled to be constant atabout 0.3 clo. Therefore, the UTCI suffers similar limitationsas WBGT and PHS indices for the assessment of heatstress when wearing protective clothing.
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| 28. |
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| 29. |
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| 30. |
- Gao, Chuansi, et al.
(författare)
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Cooling vests with phase change material packs: the effects of temperature gradient, mass, and covering area
- 2010
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Ingår i: Ergonomics. - : Informa UK Limited. - 0014-0139 .- 1366-5847. ; 53:5, s. 716-723
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Tidskriftsartikel (refereegranskat)abstract
- Phase change material (PCM) absorbs or releases latent heat when it changes phases, making thermal-regulated clothing possible. The objective of this study was to quantify the relationships between PCM cooling rate and temperature gradient, mass, and covering area on a thermal manikin in a climatic chamber. Three melting temperatures (24, 28, 32 °C) of the PCMs, different mass, covering areas, and two manikin temperatures (34 and 38 °C) were used. The results showed that the cooling rate of the PCM vests tested is positively correlated with the temperature gradient between the thermal manikin and the melting temperature of the PCMs. The required temperature gradient is suggested to be greater than 6 °C when PCM vests are used in hot climates. With the same temperature gradient, the cooling rate is mainly determined by the covering area. The duration of the cooling effect is dependent on PCM mass and the latent heat
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| 31. |
- Gao, Chuansi, et al.
(författare)
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Cooling vests with phase change materials: the effects of melting temperature on heat strain alleviation in an extremely hot environment
- 2011
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 111:6, s. 1207-1216
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Tidskriftsartikel (refereegranskat)abstract
- A previous study by the authors using a heated thermal manikin showed that the cooling rates of phase change material (PCM) are dependent on temperature gradient, mass, and covering area. The objective of this study was to investigate if the cooling effects of the temperature gradient observed on a thermal manikin could be validated on human subjects in extreme heat. The subjects wore cooling vests with PCMs at two melting temperatures (24 and 28°C) and fire-fighting clothing and equipment, thus forming three test groups (vest24, vest28 and control group without the vest). They walked on a treadmill at a speed of 5 km/h in a climatic chamber (air temperature = 55°C, relative humidity = 30%, vapour pressure = 4,725 Pa, and air velocity = 0.4 m/s). The results showed that the PCM vest with a lower melting temperature (24°C) has a stronger cooling effect on the torso and mean skin temperatures than that with a higher melting temperature (28°C). Both PCM vests mitigate peak core temperature increase during the resting recovery period. The two PCM vests tested, however, had no significant effect on the alleviation of core temperature increase during exercise in the heat. To study the possibility of effective cooling of core temperature, cooling garments with PCMs at even lower melting temperatures (e.g. 15°C) and a larger covering area should be investigated.
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| 32. |
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| 33. |
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| 34. |
- Gao, Chuansi, et al.
(författare)
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Fashion and function: challenges faced by textiles incorporated with phase change materials
- 2014
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Ingår i: [Host publication title missing]. - 2342-4540.
-
Konferensbidrag (refereegranskat)abstract
- Designers focus on fashion and appearance, whereas safety and protection engineers and physiologists emphasize functions in terms of developing functional and protective clothing. Phase change materials (PCMs) have been used in textiles and clothing to achieve cooling or warming function. The objective of this paper was to compare effectiveness of PCM cooling or warming determined by critical factors. Cooling or warming effectiveness and duration were directly dependent on physical activity level (body heat production), PCM mass and temperature gradient between the skin temperature and PCM phase change temperature. Given these factors, textiles and clothing incorporated with PCMs may be lightweight, well-designed, smart and fashionable, but are insufficiently functional when the amount of the PCM and latent heat are small relative to the body heat production and duration of activities. It is therefore challenging by incorporating PCMs into textiles and clothing to achieve desirable light weight, fashion, thermal comfort and effective alleviation of body heat strain unless the critical factors are taken into account.
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| 35. |
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| 36. |
- Gao, Chuansi, et al.
(författare)
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Gait muscle activity during walking on an inclined icy surface
- 2008
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Ingår i: Industrial Health. - : National Institute of Industrial Health. - 1880-8026 .- 0019-8366. ; 46:1, s. 15-22
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to explain the contribution of lower extremity muscle activity to gait kinetic and kinematic adaptations for maintaining gait dynamic balance when walking on an inclined icy surface and the biomechanical mechanisms used to counteract slip risk. A two-way factorial experimental design was applied. The two independent variables were the walkway surface (ice and treadmill) and the walkway inclination (0º, 6º, 8º). The dependent variable was the amplitude of the surface EMG of four right lower extremity muscles (tibialis anterior TA, gastrocnemius lateralis GL, rectus femoris RF, and biceps femoris BF). Twelve healthy subjects (7 males and 5 females) participated in the walking trials. A two-way ANOVA analysis showed that on the icy surface in the heel contact phase, EMG amplitudes significantly decreased in TA and RF compared to those for the treadmill surface. In the mid-stance phase, the GL muscle activity significantly decreased on ice compared to treadmill and all four muscle activities increased significantly with the inclination. During the toe off phase, GL and RF activities increased with the inclination. The mechanisms identified may be applied to develop intervention, rehabilitation and training techniques, and to improve performance in human locomotion, such as for winter sports.
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| 37. |
- Gao, Chuansi, et al.
(författare)
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Halk- och fallolyckor, friktionskrav och balansförmåga
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med detta projekt var att studera samspelet mellan friktion, balansförmåga och halkrisker, samt att ta fram designrekommendationer för friktionskrav och halksäkrare skor och underlag. Sex studier har utförts innefattande friktionsmätningar av skor på olika underlag och temperaturer, studier av stående balans och gång på ramp med justerbar lutning samt fokusgruppintervjuer. Resultaten visar att vid arbete i rumstemperatur på våta klinkergolv bör skosulor av polyuretan användas då de ger högre friktion, utomhus på isigt underlag bör skor med gummi eller latexsulor användas. Oavsett skosulans material och mönster hade alla testade skor utom de dubbade mycket låg friktion på is med vatten. Mjukare material på skosulor bör användas i kyla. Stående tester på plan eller lutande balansplatta med två ytmaterial, takpapp och halt underlag, visade att mer friktion utnyttjades då underlaget lutades. Både underlagets lutning och friktion påverkade balansförmågan. Alla förändringar var tydligare för det hala underlaget, låg friktion är en riskfaktor för att tappa balansen, inte bara vid gång utan också vid stående arbete. Intervjuerstudien visade att upplevda halkrisker var relaterade till hala och lutande underlag och/eller våta eller snöiga skor. Kriterier för en halkfri vintersko var flexibilitet, komfort, multifunktionalitet, ergonomiskt design, individuell anpassning, stabilitet och gångsäkerhet samt anpassning till arbetssituation. Samband mellan friktionskrav och halkrisk på en ramp med olika lutningsvinklar och ytmaterial visade att ju högre lutningsvinkel, dess högre halkrisk och högre friktionskrav vid gång nedåt på både torr och våt stålplåt. Vått underlag och högre grad av lutning bör undvikas. Ett linjärt förhållande har identifierats mellan friktionskrav och lutningsvinkel, där friktionskrav för olika lutningsvinklar kan förutsägas. Ny kunskap om prevention av halk- och fallolyckor, utformning av halksäkrare skor och arbetsplatser har erhållits i projektet.
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| 38. |
- Gao, Chuansi
(författare)
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Identification and evaluation of slip and fall risk on ice and snow
- 2001
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Roads and pavements covered with ice and snow during winter in the Nordic and other cold regions are slippery, which result in the prevalence of slip and fall accidents among not only the public, but also outdoor workers. Literature and injury statistics revealed that the most frequently specified contributory factor for occupational slip, trip and fall accidents in Sweden is snow and ice. Road accident research showed that the largest numbers of traffic casualties occurred during walking, followed by cycling and vehicle transporting. The cost to the community of providing medical treatment to victims of pedestrian injuries resulting from slipping is far greater than that of keeping walking surfaces free from ice and snow. However, in comparison with the size of the problem, little research has been carried out to identify and evaluate slip and fall risk on icy surfaces. Objectives are to present a systems perspective of slip and fall accident, to measure, evaluate and compare the coefficient of friction (COF) of footwear on ice and lubricated floor, to identify advantages of walking experience on icy surface and participating in winter sport in preventing slip and fall accidents, to develop subjective evaluation method for slipperiness measurement and usability assessment of footwear product, to systematically assess the integration of slip resistance, thermal insulation, and usability of footwear, to ascertain the anti-slip effect of materials spread on ice by user trials, and to explore the incorporated approach towards the design of footwear for use on icy surfaces. The following methods of collecting data were used in studies of this thesis: 1) direct observation, 2) videotaping, 3) human perception rating scale, 4) objective COF measurements, 5) retrospective cross-sectional epidemiological study by questionnaire. a systems model involving potential factors was proposed based on a comprehensive literature review (study I). Comparison of objective evaluation of footwear slipperiness on ice and oily floor was used to examine the frictional performance on different underfoot surfaces (study II). Epidemiological survey of slip and fall accidents was carried out focusing on individual experience, winter participation, severity of injuries, footwear, and underfoot surface conditions (study III). Subjective rating scale was developed and used to assess the perception of slip and fall risk and the usability of footwear used on various icy surfaces including anti slip materials spread on ice (study IV). The integration of multiple protection function and usability into winter footwear was also assessed (study IV). A systematic analysis of the slips and falls on icy and snowy surfaces showed that the etiology of slips and falls is multi-faceted. The COF on ice by objective measurements at 0ºC is much lower than that at -12ºC and that on stainless steel. Polyurethane soling material did not provide sufficient friction on wet ice at least when new (without abrasion), although superior on lubricated floors. The footwear tested including winter footwear, professional footwear, safety footwear, and footwear deemed to be slip resistant by users and manufacturers did not provide sufficient protection against slips and falls on wet ice at around 0ºC. Accordingly, slip and fall risk is higher on wet ice than on dry ice and lubricated floor. Slip and fall events reduced with increased living experience in cold environments and winter sport participation. Newcomers with no or less experience were prone to falling, and therefore they should be well informed of potential slip and fall hazards upon arrival in cold region. Slip resistance, thermal insulation and usability of footwear tested were not properly integrated. In addition to thermal insulation, prevention of slip and fall hazard by improving anti-slip property and usability must also be priorities for development of footwear for use in cold environments. Based on the findings, anti-slip footwear, measurement methods for slipperiness on ice and snow, related standards, the role of gait biomechanics and task-related factors should be further developed and studied.
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| 39. |
- Gao, Chuansi, et al.
(författare)
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Initial, transient and steady state evaporative resistance of impermeable protective clothing
- 2006
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Ingår i: [Host publication title missing]. - 9623675348 ; , s. 253-261
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Konferensbidrag (refereegranskat)abstract
- The measured water vapour resistances of clothing ensembles differ among laboratories particularly for impermeable clothing. Due to the moisture transfer in the clothing ensemble, evaporative heat losses in initial, transient and steady state phases are different. The purpose of this study was to investigate moisture absorption inside underwear and outer layer as a function of time, to quantify the difference of water vapour resistance of protective clothing (impermeable outer layer and cotton underwear) in initial, transient and steady state. Manikin Tore was used by wearing wet ‘skin’ to simulate sweating. The evaporative resistance is found to be more than two times higher in the initial phase than that in the saturation phase. The moisture content is gained exponentially in the clothing ensemble. On the contrary, mass loss directly from the wet skin decreases exponentially. These may partly explain the poor reproducibility while measuring the evaporative resistance of impermeable clothing for a short period.
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| 40. |
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| 41. |
- Gao, Chuansi, et al.
(författare)
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Moisture absorption, mass loss and evaporative resistance of permeable clothing in a transient condition
- 2006
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Ingår i: Journal of Donghua University. - 1672-5220. ; 23:5, s. 54-58
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Tidskriftsartikel (refereegranskat)abstract
- The water vapour resistance of clothing ensembles is not as commonly determined as dry thermal insulation. The measurement techniques are more complicated and the measurement values differ among laboratories. Due to complicated moisture transfer process through clothing ensemble, the moisture absorbed and evaporated varies in transient and steady state phases depending on properties, thickness of clothing, and environmental conditions. The purpose of this study was to measure moisture absorption inside hygroscopic underwear, hydrophobic and permeable outer wear as a function of time, to investigate mass loss from “skin” as well as from manikin, to quantify evaporative heat loss and total heat loss from manikin, to determine evaporative resistance of clothing. Manikin Tore was used by wearing wet “skin” to simulate sweating. Moisture content gain of the inner garment shows an exponential relation against time. Moisture in the outer permeable garment shows very small gain. On the contrary, mass loss directly from the wet skin decreases exponentially. The mass loss from the manikin is relatively stable throughout three test phases. The evaporative heat loss is about two thirds of the total heat loss from the sweating manikin. One hour measurement time is sufficient to get stable results while measuring the evaporative resistance of clothing ensembles with hygroscopic inner garment and permeable outer garment. The variation between the 1st hour and the 3rd hour is less than 5%. The length of transient period and measurement time requirement is dependent on the permeability, thickness of clothing ensembles and environmental conditions.
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| 42. |
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| 43. |
- Gao, Chuansi, et al.
(författare)
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Occupational heat stress assessment and protective strategies in the context of climate change
- 2018
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Ingår i: International Journal of Biometeorology. - : Springer Science and Business Media LLC. - 1432-1254 .- 0020-7128. ; 62:3, s. 359-371
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Tidskriftsartikel (refereegranskat)abstract
- Global warming will unquestionably increase the impact of heat on individuals who work in already hot workplaces in hot climate areas. The increasing prevalence of this environmental health risk requires the improvement of assessment methods linked to meteorological data. Such new methods will help to reveal the size of the problem and design appropriate interventions at individual, workplace and societal level. The evaluation of occupational heat stress requires measurement of four thermal climate factors (air temperature, humidity, air velocity and heat radiation); available weather station data may serve this purpose. However, the use of meteorological data for occupational heat stress assessment is limited because weather stations do not traditionally and directly measure some important climate factors, e.g. solar radiation. In addition, local workplace environmental conditions such as local heat sources, metabolic heat production within the human body, and clothing properties, all affect the exchange of heat between the body and the environment. A robust occupational heat stress index should properly address all these factors. This article reviews and highlights a number of selected heat stress indices, indicating their advantages and disadvantages in relation to meteorological data, local workplace environments, body heat production and the use of protective clothing. These heat stress and heat strain indices include Wet Bulb Globe Temperature, Discomfort Index, Predicted Heat Strain index, and Universal Thermal Climate Index. In some cases, individuals may be monitored for heat strain through physiological measurements and medical supervision prior to and during exposure. Relevant protective and preventive strategies for alleviating heat strain are also reviewed and proposed.
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| 44. |
- Gao, Chuansi, et al.
(författare)
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Perception of slipperiness, thermal comfort and wearability of footwear used on icy surfaces
- 2000
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Ingår i: Ergonomics for the new Millenium. - : Human Factors and Ergonomics Society. - 0945289138 ; , s. 522-525
-
Konferensbidrag (refereegranskat)abstract
- The objectives of this study are to assess the perception of slipperiness, thermal comfort, and wearability of footwear used on icy surfaces, and the anti-slip effect of materials spread on ice using outdoor walking trials. Twenty-five subjects wore four types of footwear walking on five different icy surfaces. A five-point rating scale was used recording wearer's perception. The results showed that pure ice was perceived as very slippery. Spreading sand (180 g/m2) greatly decreased the slipperiness. Slip resistance, thermal insulation and wearability of footwear chosen were not properly integrated, and were ranked differently in four types of footwear. In addition to thermal insulation, prevention of slip and fall hazard by improving anti-slip property and wearability must also be priorities for development of footwear for use in a cold climate.
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| 45. |
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| 46. |
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| 47. |
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| 48. |
- Gao, Chuansi, et al.
(författare)
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Personal cooling with phase change materials to improve thermal comfort from a heat wave perspective
- 2012
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Ingår i: Indoor Air. - : Hindawi Limited. - 0905-6947. ; 22:6, s. 523-530
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedAbstract The impact of heat waves arising from climate change on human health is predicted to be profound. It is important to be prepared with various preventive measures for such impacts on society. The objective of this study was to investigate whether personal cooling with phase change materials (PCM) could improve thermal comfort in simulated office work at 34°C. Cooling vests with PCM were measured on a thermal manikin before studies on human subjects. Eight male subjects participated in the study in a climatic chamber (T(a) = 34°C, RH = 60%, and ν(a) = 0.4 m/s). Results showed that the cooling effect on the manikin torso was 29.1 W/m(2) in the isothermal condition. The results on the manikin using a constant heating power mode reflect directly the local cooling effect on subjects. The results on the subjects showed that the torso skin temperature decreased by about 2-3°C and remained at 33.3°C. Both whole body and torso thermal sensations were improved. The findings indicate that the personal cooling with PCM can be used as an option to improve thermal comfort for office workers without air conditioning and may be used for vulnerable groups, such as elderly people, when confronted with heat waves. PRACTICAL IMPLICATIONS: Wearable personal cooling integrated with phase change materials has the advantage of cooling human body's micro-environment in contrast to stationary personalized cooling and entire room or building cooling, thus providing greater mobility and helping to save energy. In places where air conditioning is not usually used, this personal cooling method can be used as a preventive measure when confronted with heat waves for office workers, vulnerable populations such as the elderly and disabled people, people with chronic diseases, and for use at home.
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| 49. |
- Gao, Chuansi
(författare)
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Phase-change materials (PCMs) for warming or cooling in protective clothing
- 2014
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Ingår i: Protective Clothing : Managing Thermal Stress - Managing Thermal Stress. - : Elsevier. - 9781782420323 - 9781782420408 ; , s. 227-249
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Bokkapitel (refereegranskat)abstract
- The various types of phase-change materials (PCMs), which absorb or release stored latent heat when they change phases causing cooling and warming effects, are described and the working principles are outlined. The various ways of incorporating PCMs into textiles for protective clothing are explored, and critical factors identified that determine the effectiveness of PCM cooling and warming effects. Examples of applications are given. Standards and testing, future trends and challenges are discussed.
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| 50. |
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