| 1. |
- Reithmaier, Gloria M.S., et al.
(author)
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Carbonate chemistry and carbon sequestration driven by inorganic carbon outwelling from mangroves and saltmarshes
- 2023
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In: Nature Communications. - 2041-1723. ; 14:1
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Journal article (peer-reviewed)abstract
- Mangroves and saltmarshes are biogeochemical hotspots storing carbon in sediments and in the ocean following lateral carbon export (outwelling). Coastal seawater pH is modified by both uptake of anthropogenic carbon dioxide and natural biogeochemical processes, e.g., wetland inputs. Here, we investigate how mangroves and saltmarshes influence coastal carbonate chemistry and quantify the contribution of alkalinity and dissolved inorganic carbon (DIC) outwelling to blue carbon budgets. Observations from 45 mangroves and 16 saltmarshes worldwide revealed that >70% of intertidal wetlands export more DIC than alkalinity, potentially decreasing thepH of coastal waters. Porewater-derived DIC outwelling (81 ± 47 mmol m−2 d−1 in mangroves and 57 ± 104 mmol m−2 d−1 in saltmarshes) was the major term in blue carbon budgets. However, substantial amounts of fixed carbon remain unaccounted for. Concurrently, alkalinity outwelling was similar or higher than sediment carbon burial and is therefore a significant but often overlooked carbon sequestration mechanism.
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| 2. |
- Wang, Faming, et al.
(author)
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Characterization on pore size of honeycomb-patterned micro-porous PET fibers using image processing techniques
- 2010
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In: Industria Textila. - 1222-5347. ; 61:2, s. 66-69
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Journal article (peer-reviewed)abstract
- This Paper Presents a method to characterize the pore structure of the fibre surface for the honeycomb-patterned PET fibers; by using scanning electron microscopy (SEM) and image processing techniques. They consist of linear channel pores (LCP) and ellipse pores The surface pore distribution and micro pore numbers varied from each fiber to another, which can make significant differences on the. property of the spun yarns. It is proposed that the fiber should be sufficiently rinsed with clean water before dewatering and Setting processes, to eliminate the pore-clogging effect.
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| 3. |
- Wang, Faming, et al.
(author)
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Development Processes and Property Measurements of Moisture Absorption and Quick Dry Fabrics
- 2009
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In: Fibres & Textiles in Eastern Europe. - 1230-3666. ; 17:2, s. 46-49
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Journal article (peer-reviewed)abstract
- In this study a new type of honeycomb-patterned micro-porous polyester fibre was used to develop good moisture absorption and quick drying properties of woven fabrics. Details of the development and after-finish processes of the fabrics were illustrated. The water transport, vapour transmission and quick dry properties of the seven different end products were also investigated. It was evident that weaving parameters and after-finish processes are crucial factors in the fabric production process. The final products can also have good water transport and quick dry properties without additive treatment.
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| 4. |
- Wang, Faming, et al.
(author)
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Empirical Equations for Intrinsic and Effective Evaporative Resistances of Multi-layer Clothing Ensembles
- 2010
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In: Industria Textila. - 1222-5347. ; 61:4, s. 176-180
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Journal article (peer-reviewed)abstract
- To determine the intrinsic and effective clothing evaporative resistances,both in the individual clothing, and in the nulti-layer clothing ensembles meant for winter season, a fabric sweating thermal manikin Walter was used. Based on the tests performed on the individual garments, two empirical equations were developed for the estimation of these resistances, useful either to clothing manufacturers- to roughly estimate the clothing intrinsic/effective evaporative resistance, or to consumers-to assure them an optimal thermal comfort.
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| 5. |
- Yang, Bin, et al.
(author)
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Non-invasive (non-contact) measurements of human thermal physiology signals and thermal comfort/discomfort poses -A review
- 2020
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In: Energy and Buildings. - : ELSEVIER SCIENCE SA. - 0378-7788 .- 1872-6178. ; 224
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Research review (peer-reviewed)abstract
- Heating, ventilation and air-conditioning (HVAC) systems have been adopted to create comfortable, healthy and safe indoor environments. In the control loop, the technical feature of the human demand-oriented supply can help operate HVAC effectively. Among many technical options, real time monitoring based on feedback signals from end users has been frequently reported as a critical technology to confirm optimizing building performance. Recent studies have incorporated human thermal physiology signals and thermal comfort/discomfort status as real-time feedback signals. A series of human subject experiments used to be conducted by primarily adopting subjective questionnaire surveys in a lab-setting study, which is limited in the application for reality. With the help of advanced technologies, physiological signals have been detected, measured and processed by using multiple technical formats, such as wearable sensors. Nevertheless, they mostly require physical contacts with the skin surface in spite of the small physical dimension and compatibility with other wearable accessories, such as goggles, and intelligent bracelets. Most recently, a low cost small infrared camera has been adopted for monitoring human facial images, which could detect the facial skin temperature and blood perfusion in a contact less way. Also, according to latest pilot studies, a conventional digital camera can generate infrared images with the help of new methods, such as the Euler video magnification technology. Human thermal comfort/discomfort poses can also be detected by video methods without contacting human bodies and be analyzed by the skeleton keypoints model. In this review, new sensing technologies were summarized, their cons and pros were discussed, and extended applications for the demand-oriented ventilation were also reviewed as potential development and applications.
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| 6. |
- Zhao, Mengmeng, et al.
(author)
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The Effect of Flow Rate of a Short Sleeve Air Ventilation Garment on Torso Thermal Comfort in a Moderate Environment
- 2022
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In: Fibers and Polymers. - : Springer Science and Business Media LLC. - 1229-9197 .- 1875-0052. ; 23:2, s. 546-553
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Journal article (peer-reviewed)abstract
- In recent years, air ventilation garments (AVG) have been reported effective to improve thermal comfort. In this study, an AVG incorporated with small fans was investigated on torso thermal comfort in moderate environment (Ta=25 °C, RH=50 %). Eight female subjects walked on the treadmill at a speed of 4 km·h−1 for 30 min and then rested for another 30 min. During the whole test protocol, the AVG was worn in three conditions of flow rates to examine which flow rate was the best choice to keep thermal comfort: fans off with no air ventilation (a controlled condition, CON), low flow rate (12 l/s, LOW) and high flow rate (20 l/s, HIGH). Results showed that HIGH made significantly lowered local skin temperature of the abdomen, scapula and the lower back (p<0.05). The mean torso skin temperature in CON, LOW and HIGH in the last 5 min in the exercising stage was 32.3, 30.2 and 29.2 °C, respectively and it was 32.1, 29.5 and 28.2 °C, respectively in the resting stage. HIGH significantly mitigated thermal sensation in the 40 and 50th min (p<0.05), whereas it produced cool and unpleasant thermal sensation in the resting stage. In the whole test scenario, LOW produced the best torso thermal comfort. The low flow rate of ventilation (12 l/s) should be recommend and used in such a moderate environment to maintain torso thermal comfort.
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| 7. |
- Cheng, Xiaogang, et al.
(author)
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Contactless sleep posture measurements for demand-controlled sleep thermal comfort : a pilot study
- 2022
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In: Indoor Air. - : Wiley-Blackwell. - 0905-6947 .- 1600-0668. ; 32:12
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Journal article (peer-reviewed)abstract
- Thermal comfort during sleep is essential for both sleep quality and human health while sleeping. There are currently few effective contactless methods for detecting the sleep thermal comfort at any time of day or night. In this paper, a vision-based detection approach for human thermal comfort while sleeping was proposed, which is intended to avoid overcooling/overheating supply, meet the thermal comfort needs of human sleep, and improve human sleep quality and health. Based on 438 valid questionnaire surveys, 10 types of thermal comfort sleep postures were summarized. By using a large number of data captured, a fundamental framework of detection algorithm was constructed to detect human sleeping postures, and corresponding weighting model was established. A total of 2.65 million frames of posture data in natural sleep status were collected, and thermal comfort-related sleep postures dataset was created. Finally, the robustness and effectiveness of the proposed algorithm were validated. The validation results show that the sleeping posture and human skeleton keypoints can be used for estimating sleeping thermal comfort, and the the quilt coverage area can be fused to improve the detection accuracy.
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| 8. |
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| 9. |
- Gao, Chuansi, et al.
(author)
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Clothing Insulation Required for Energy Efficiency (IREQee) and Thermal Comfort
- 2016
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In: Proceedings of the 11th International Meeting on Thermal Manikin and Modeling(11i3m). - 9789887766209 ; , s. 28-29
-
Conference paper (peer-reviewed)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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| 10. |
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| 11. |
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| 12. |
- Gao, Chuansi, et al.
(author)
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Personal cooling with phase change materials to improve thermal comfort from a heat wave perspective
- 2012
-
In: Indoor Air. - : Hindawi Limited. - 0905-6947. ; 22:6, s. 523-530
-
Journal article (peer-reviewed)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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| 13. |
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| 14. |
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| 15. |
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| 16. |
- Ke, Ying, et al.
(author)
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On the use of a novel nanoporous polyethylene (nanoPE) passive cooling material for personal thermal comfort management under uniform indoor environments
- 2018
-
In: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 145, s. 85-95
-
Journal article (peer-reviewed)abstract
- Passive cooling materials such as specially designed nanoporous microfibers are nearly transparent to infrared thermal radiation emitted from the human body. Hence, such passive cooling materials have the potential to help indoor occupants attain thermal comfort through regulating the radiative body heat in indoor conditions. In this work, a regular fit women's business shirt made of the nanoporous polyethylene (nanoPE) material was designed and its cooling performance under four uniform indoor conditions was examined. A cotton shirt (CO) with the same size and pattern as the nanoPE shirt was designed and selected as the control. Eighteen female participants underwent eight 80-min trials at four indoor temperatures: 23, 25, 27 and 29 °C. Trials were performed in simulated indoor environments where RH = 60% and the air velocity was kept below 0.10 m/s. Results have demonstrated that participants had significantly lower mean skin temperatures, mean upper torso temperatures and forearm temperatures in nanoPE as compared to CO at 23, 25 and 27 °C. Participants showed the maximum satisfaction with the thermal environment while wearing the CO clothing at 25 °C, whereas they were mostly satisfied with the thermal environment while wearing the nanoPE clothing at 27 °C. Thus, the acceptable air conditioning setpoint temperature could be extended by 1.5 °C from 25.5 to 27 °C while using the nanoPE clothing and thereby, this saves about 9–15% cooling energy. Finally, it was concluded that the nanoPE passive cooling clothing contributes to enhancing indoor thermal comfort under uniform environments and saving significant cooling energy.
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| 17. |
- Kuklane, Kalev, et al.
(author)
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European manikin standards and models to calculate thermal insulation
- 2010
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In: 8I3M : Eighth International Meeting for Manikins and Modeling : Victoria, BC, Canada, August 22-26, 2010 - Eighth International Meeting for Manikins and Modeling : Victoria, BC, Canada, August 22-26, 2010.
-
Conference paper (peer-reviewed)abstract
- ISO 9920 defines three insulation calculation methods: global, parallel and serial. It considers global method a general one that works in any situation, and parallel and serial could be used in specific cases. EN ISO 15831 is the basic manikin testing standard. It gives only two possibilities: parallel and serial. The specific requirements for equations’ use are not set as in ISO 9920, e.g. uniform heat loss or surface temperature. The parallel method is defined similarly to the global in ISO 9920. Thus, the calculation methods’ definitions in the standards differ. EN 342, EN 14058 and EN 13537 for testing cold protective clothing or equipment refer to the methods in EN ISO 15831. Calculation of insulation by any method or using the average insulation of both methods is allowed depending on the test results with reference calibration ensembles. However, several issues need to be considered when using serial method. EN 511 Protective gloves against cold gives its own equation assuming that the whole hand is just one zone. In the case of one zone the serial and the parallel model give the same result. More zones increase the insulation difference between the methods. With uniform surface temperature (required by EN ISO 15831) the parallel method provides the same insulation value with any number of zones while the serial method provides higher value with more zones compared to one zone. EN 342 (cold) and EN 14058 (cool) use the same measuring principles and the same calibration garments. In the case of evenly distributed insulation, the differences in serial and parallel methods are relatively small, and proportional. However, with more insulation layers overlapping in heavy cold protective ensembles the differences increase, and don’t follow the linear relationship any more. The calibration ensembles are selected to represent proper cold protective garments. Thus, if a garment piece does not represent a proper cold protective ensemble (faulty design, manufacturing error) the calibration does not have to be valid. Lately a study on insulation measurements with electrically heated vest was presented. The vest provided an additional 10 W totally to torso region, and turned results from serial method to impossible 83 clo. It may be argued that manikin test is not meant to measure clothing with auxiliary heating. However, what happens if components of an ensemble do employ smart textile technology? A standard should avoid allowing any unrealistic results. EN 13537 Requirements for sleeping bags utilizes the physiological model that has been developed assuming serial values to be correct. It works with properly manufactured sleeping bags. It would be a considerable work to replace the method, although, equally good models are available. Such a major change requires good will and participation from several labs including the ones outside Europe, too.
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| 18. |
- Kuklane, Kalev, et al.
(author)
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Parallel and serial methods of calculating thermal insulation in European manikin standards
- 2012
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In: International Journal of Occupational Safety and Ergonomics. - 2376-9130. ; 18:2, s. 171-179
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Journal article (peer-reviewed)abstract
- Standard No. EN 15831:2004 provides 2 methods of calculating insulation: parallel and serial. The parallel method is similar to the global one defined in Standard No. ISO 9920:2007. Standards No. EN 342:2004, EN 14058:2004 and EN 13537:2002 refer to the methods defined in Standard No. EN ISO 15831:2004 for testing cold protective clothing or equipment. However, it is necessary to consider several issues, e.g., referring to measuring human subjects, when using the serial method. With one zone, there is no serial–parallel issue as the results are the same, while more zones increase the difference in insulation value between the methods. If insulation is evenly distributed, differences between the serial and parallel method are relatively small and proportional. However, with more insulation layers overlapping in heavy cold protective ensembles, the serial method produces higher insulation values than the parallel one and human studies. Therefore, the parallel method is recommended for standard testing.
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| 19. |
- Lin, Li-Yen, et al.
(author)
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A laboratory validation study of comfort and limit temperatures of four sleeping bags defined according to EN 13537 (2002)
- 2013
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In: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 44:2, s. 321-326
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Journal article (peer-reviewed)abstract
- In this study, we validated comfort and limit temperatures of four sleeping bags with different levels of insulation defined according to EN 13537. Six male subjects and four female subjects underwent totally 20 two-hour exposures in four sleeping bags at four intended testing temperatures: 11.2, 3.8, 2.1 and -9.0 degrees C. The subjective perceptions and physiological responses of these subjects were reported and analyzed. It was found that the EN 13537 defined comfort temperature and limit temperature were underestimated for sleeping bags MA3, HAG and MAM. The predictions are so conservative that further revision may be required to meet the requirements of both manufacturers and consumers. In contrast, for the sleeping bag MAO with a low level of insulation, the limit temperature defined by EN 13537 was slightly overestimated. In addition, two individual case studies (-28.0 and -32.0 degrees C) demonstrated that low toe temperatures were widely observed among the male and female subjects, although the mean skin temperatures were almost within the thermoneutrality range (32.0-34.0 degrees C). It seems that the IREQ model (ISO 11079) overestimated both the comfort and limit temperatures of the sleeping bags. Finally, traditional sleeping bags may be required to be re-designed to provide consumers both whole body comfort as well as local thermal comfort at feet/toes or users need to be made aware of the higher need for their insulation. (C) 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.
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| 20. |
- Lu, Yehu, et al.
(author)
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A novel personal cooling system (PCS) incorporated with phase change materials (PCMs) and ventilation fans: An investigation on its cooling efficiency
- 2015
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In: Journal of Thermal Biology. - : Elsevier BV. - 0306-4565. ; 52, s. 137-146
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Journal article (peer-reviewed)abstract
- Personal cooling systems (PCS) have been developed to mitigate the impact of severe heat stress for humans working in hot environments. It is still a great challenge to develop PCSs that are portable, inexpensive, and effective. We studied the performance of a new hybrid PCS incorporating both ventilation fans and phase change materials (PCMs). The cooling efficiency of the newly developed PCS was investigated on a sweating manikin in two hot conditions: hot humid (HH, 34 °C, 75% RH) and hot dry (HD, 34 °C, 28% RH). Four test scenarios were selected: fans off with no PCMs (i.e., Fan-off, the CONTROL), fans on with no PCMs (i.e., Fan-on), fans off with fully solidified PCMs (i.e., PCM+Fan-off), and fans on with fully solidified PCMs (i.e., PCM+Fan-on). It was found that the addition of PCMs provided a 54∼78 min cooling in HH condition. In contrast, the PCMs only offered a 19–39 min cooling in HD condition. In both conditions, the ventilation fans greatly enhanced the evaporative heat loss compared with Fan-off. The hybrid PCS (i.e., PCM+Fan-on) provided a continuous cooling effect during the three-hour test and the average cooling rate for the whole body was around 111 and 315 W in HH and HD conditions, respectively. Overall, the new hybrid PCS may be an effective means of ameliorating symptoms of heat stress in both hot-humid and hot-dry environments.
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| 21. |
- Mayor, Tiago, et al.
(author)
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An interlaboratory study on measurements of clothing evaporative resistance with thermal manikins
- 2012
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In: ; , s. 1-4
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Conference paper (peer-reviewed)abstract
- Abstract in UndeterminedAn interlaboratory study on measurement of evaporative resistance (Ret) with thermal manikins has been conducted in order to assess the repeatability and reproducibility limits as a function of mean resistance values, when using similar test protocols (ASTM F2370). Three independent laboratories tested seven clothing ensembles, with Ret ranging from very low to very high values (20-325 m2∙Pa/W). The repeatability and the reproducibility limits were found to vary in the ranges 3-15% and 12-24%, respectively, for ensembles with a Ret value up to 60 m2∙Pa/W. These parameters escalated to 21-27% and 51-53%, for ensembles with higher Ret (110-325 m2∙Pa/W). The high relative error in the measurements of local manikin heat losses was found to play a relevant role, particularly for the most impermeable samples.
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| 22. |
-
Protective clothing: managing thermal stress
- 2014
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Editorial collection (other academic/artistic)abstract
- Protective clothing protects wearers from hostile environments, including extremes of heat and cold. Whilst some types of protective clothing may be designed primarily for non-thermal hazards (e.g. biological hazards), a key challenge in all protective clothing remains wearer comfort and the management of thermal stress (i.e. excessive heat or cold). This book reviews key types of protective clothing, technologies for heating and cooling and, finally, modeling aspects of thermal stress and strain. Explores different types of protective clothing, their uses and their requirements, with an emphasis on full-scale or prototype clothing, including immersion suits, body armour and space suits Considers novel and commercial technologies for regulating temperature in protective clothing, including phase change materials, shape memory alloys, electrically heated clothing and air and water perfusion-based cooling systems Reviews the human thermoregulatory system and the methods of modelling of thermal stress in protective clothing through various conditions, including cold water survival and firefighting.
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| 23. |
- Raj, Uday, et al.
(author)
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A study of thermal comfort enhancement using three energy efficient personalized heating strategies at two low indoor temperatures
- 2018
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In: Building and Environment. - : Pergamon Press. - 0360-1323 .- 1873-684X. ; 143, s. 1-14
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Journal article (peer-reviewed)abstract
- There is great potential to apply personalized heating for saving energy and enhancing individual thermal comfort in buildings during cold weather. This study investigated the enhancement of thermal comfort of occupants using personalized heating systems at low indoor temperatures. Three personalized heating systems are chosen for this work, i.e., a radiant heating panel with a heated table pad (denoted as HB1), a heated chair with a heated floor mattress (denoted as HB2), and electrical heating clothing (a heated jacket and trousers, denoted as EHC). The effectiveness of three selected heating systems on overall/local body thermal comfort of female occupants under two indoor temperatures of 15 and 18 degrees C has been investigated. Total energy consumption of these heating systems has also been examined and compared. Thermal acceptability of EHC was better than HB1 and HB2 at both two temperatures. Overall thermal sensation vote (TSV) in EHC was significantly better than that in HB1. Mean skin temperature remained within the thermal comfort range (32-34 degrees C). In order to achieve thermal comfort on 70% and 80% of the inhabitants at various body parts, local body TSVs should be within - 0.43 to 1.87 and - 0.36 to 1.87, respectively. Further, EHC consumed < 15 W power, which accounts for only 4.4% and 14.8% of the total power consumed by HB1 and HB2, respectively. Based on the evidenced thermal comfort improvement potential and low power consumption in EHC, it is thus recommended to use EHC for the thermal comfort enhancement of inhabitants under low indoor temperatures.
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| 24. |
- Raj, Uday, et al.
(author)
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Personal cooling strategies to improve thermal comfort in warm indoor environments: comparison of a conventional desk fan and air ventilation clothing
- 2018
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In: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 174, s. 439-451
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Journal article (peer-reviewed)abstract
- The study examined and compared the performance of two personalized cooling strategies (conventional desk fan [DF] and air ventilation clothing [VC]) in three warm indoor environments. Two cooling methods were selected so that the effect of different local body parts cooling can be analysed on overall thermal comfort of female participants. Three warm indoor conditions (28.0, 30.0 and 32.0 °C; 50% RH) were selected with an aim to determine maximum possible air temperature which can be maintained indoors without compromising with thermal comfort of inhabitants. Results showed that performance of both the two cooling methods are similar in terms of perceptual responses and mean skin temperatures at all three air temperatures. Mean torso temperatures in VC were significantly lower than those in DF at three studied indoor temperatures. It was concluded that the effect of torso cooling on overall sensations was equivalent to combined forehead-hand cooling for the studied indoor conditions. VC is recommended for indoor and normal office work environments with air temperatures up to 32.0 °C because it can save significant cooling energy as compared to conventional desk fans.
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| 25. |
- Su, Wei, et al.
(author)
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A novel convection and radiation combined terminal device : Its impact on occupant thermal comfort and cognitive performance in winter indoor environments
- 2021
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In: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 246
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Journal article (peer-reviewed)abstract
- Personal comfort systems usually use a single heat transfer mode to improve local thermal comfort by only stimulating one local body part. A novel hybrid convection and radiation combined terminal device, which could be used both in summer and winter, was proposed. A total of sixteen human subjects took part in a winter subjective experiment to test its performance on the improvement of occupants’ thermal comfort and cognitive performance in winter. Occupants’ thermal comfort, air movement perception, eye dryness and cognitive performance were investigated. The results showed that 88% of the subjects accepted 16℃ room temperature. 0.4 m/s air speed to face and abdomen parts is acceptable when convective airflow temperature is 4.5℃ higher than room temperature. No dry eye discomfort was reported while using a controllable device. Furthermore, subjects’ cognitive performance, including self-evaluate work performance, math (mental performance) and typing performance (dexterity), could be significantly improved by using the novel device. Energy efficient thermal comfort can be achieved by less intensifying ambient heating temperature to 16℃ in winter.
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| 26. |
- Su, Wei, et al.
(author)
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Infection probability under different air distribution patterns
- 2021
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In: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 207:Part B
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Journal article (peer-reviewed)abstract
- Infectious diseases have caused significant physical harm to humans as well as enormous economic losses over the years. Effective ventilation and distribution of fresh air could help to reduce indoor cross-infection. The computational fluid dynamics (CFD) method was used in this paper to investigate airborne transmission with seven different air distribution methods. The revised Wells-Riley model, which took into account the non-uniform air distribution generated with the methods, was used to calculate the infection probability in an office room shared by ten occupants for 4 h. One of the occupants was an infector. The significance of the infector's location was studied. The obtained infection probability was compared to that obtained in the case of complete air mixing, which is uncommon in practice. Under specified conditions of this study, personalized ventilation (PV) performed the best in terms of preventing cross-infection, followed by displacement ventilation (DV), impinging jet ventilation (IJV), stratum ventilation (SV) and wall attachment ventilation (WAV). The number of infected occupants was reduced below the number obtained under the complete mixing assumption by using these air distribution methods. Mixing ventilation (MV) and diffuse ceiling ventilation (DCV) exhibited the worst performance. In comparison to the case of complete mixing the infection probability for seven out of nine susceptible occupants was higher with MV and for all occupants in the case of DCV. In SV, the position of the infector had a clear impact on the infection probability of susceptible individuals. WAV may perform better in practice if the system is well designed. The location of the exhaust outlets had a significant impact on the infection probability for DCV.
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| 27. |
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| 28. |
- Wang, Faming, et al.
(author)
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A review of technology of personal heating garments.
- 2010
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In: International Journal of Occupational Safety and Ergonomics. - 2376-9130. ; 16:3, s. 387-404
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Journal article (peer-reviewed)abstract
- Modern technology makes garments smart, which can help a wearer to manage in specific situations by improving the functionality of the garments. The personal heating garment (PHG) widens the operating temperature range of the garment and improves its protection against the cold. This paper describes several kinds of PHGs worldwide; their advantages and disadvantages are also addressed. Some challenges and suggestions are finally addressed with regard to the development of PHGs.
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| 29. |
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| 30. |
- Wang, Faming, et al.
(author)
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A Study on Evaporative Resistances of Two Skins Designed for Thermal Manikin Tore under Different Environmental Conditions
- 2009
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In: Textile Bioengineering And Informatics Symposium Proceedings, Vols 1 And 2. - 1942-3438. ; , s. 211-215
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Conference paper (peer-reviewed)abstract
- A cotton skin and Gore-Tex skin were designed for thermal manikin "Tore" to simulate different sweating styles (wet cotton skin inside and Gore-Tex outside to simulate sweating style of thermal manikin "Walter", and Gore-Tex skin inside with wet cotton skin outside to simulate sweating style of thermal manikins "Newton". The evaporative resistances of two skin combinations with clothing ensembles were compared at two different environmental conditions. In addition, the total evaporative resistance of clothing ensemble was calculated by both heat loss method (option 1) and mass loss method (option 2) according to ASTM F 2370. We found that the effect of different sweating mechanisms on clothing evaporative resistance should be considered. The results showed that the total evaporative resistances obtained by option 2 were more accurate than values by option 1 under an isothermal condition. It was also found that total evaporative resistance differences between two skin combinations with clothing ensembles decreased with increasing clothing ensemble layer. In a non-isothermal condition, the total evaporative resistance calculated by option 1 was more accurate than value obtained by option 2, which was due to lower ambient temperature and condensation between each adjacent layer.
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| 31. |
- Wang, Faming, et al.
(author)
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A Study on Evaporative Resistances of Two Skins Designed for Thermal Manikin Tore under Different Environmental Conditions
- 2009
-
In: Journal of Fiber Bioengineering and Informatics. - : Textile Bioengineering and Informatics Society. - 1940-8676 .- 2617-8699. ; 1:4, s. 301-305
-
Journal article (pop. science, debate, etc.)abstract
- A cotton skin and a waterproof but permeable Gore-Tex skin were designed for the thermal manikin “Tore” to simulate different sweating styles (the wet cotton skin inside and Gore-Tex skin outside to simulate the sweating style of thermal manikin “Walter”, and Gore-Tex skin inside with wet cotton skin outside to simulate the sweating style of thermal manikins “Newton”). The evaporative resistances of two skin combinations with clothing ensembles were compared at different environmental conditions. In addition, the total evaporative resistance of clothing ensemble was calculated by both the heat loss method (option 1) and the mass loss method (option 2) according to ASTM F 2370. We found that the effect of different sweating mechanisms on the clothing evaporative resistance should be considered. The results showed that the total evaporative resistances calculated by option 2 were more accurate than values in option 1 under the isothermal condition. It was also found that differences of the total evaporative resistance between two skin combinations with clothing ensembles decreased with the increasing clothing ensemble layer. In a non-isothermal condition, the total evaporative resistance calculated by option 1 was more accurate than the value obtained in option 2, which was due to the lower ambient temperature and condensations between each adjacent layer.
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| 32. |
- Wang, Faming, et al.
(author)
-
Body-mapping nano-porous polyethylene (PE) clothing could prompt radiative body heat dissipation in moderate warm indoor environments
- 2017
-
In: The 17th International Conference on Environmental Ergonomics. - : International Society for Environmental Ergonomics.
-
Conference paper (peer-reviewed)abstract
- Extreme weather events like heatwaves and cold spells are increasing due to global warming and human-caused climate change. In hot climates and heatwave incidents, there is a huge amount of energy consumption due to indoor temperature regulation. It has been criticized that the use of air conditioning systems causes too much energy consumption due to the conditioning of large building spaces. Scientists started to seek for effective and energy-saving methods to provide people thermal comfort environments with minimal energy consumptions. One of the effective and most-often methods is the use of personal conditioning clothing such as air ventilation clothing, moisture evaporation clothing and water/air cooling clothing. Nevertheless, such person conditioning clothing still requires cooling sources and energy use. In indoor environments, the infrared radiative heat released by our human body accounts for over 50% of the total body heat. Traditional clothing made from either natural or synthetic fibres is not designed for infrared radiation management because they do prevent the infrared radiative heat from being dissipated to the indoor environment. Therefore, it would be ideal to develop novel passive personal cooling clothing without energy input for indoor occupants. In this study, we have explored the possibility of designing passive personal cooling clothing without energy input. A novel body-mapping nanoporous polyethylene uniform was developed to examine its effectiveness in dissipating infrared radiative heat loss in indoor environments. Eight female subjects voluntarily participated in this study. Each subject completed two 65- minute trials presented in a randomized order. The environmental temperature inside the climate chamber is controlled and increased in 12 equal steps from 24.0 °C to 30.0 °C (i.e., the increment rate is 0.5 °C every five minutes). Heart rate, skin temperatures at 10 local body sites and perceptual sensations such as thermal sensation, thermal preference, thermal acceptability, comfort sensation, skin humidity sensation are surveyed throughout the whole trials. Two clothing ensembles with the same design were chosen: Nanoporous PE clothing and traditional clothing (business trousers and long-sleeve shirt). It was found that the mean skin temperature started to rise at 26.0 °C when wearing cotton clothing while the mean skin temperature increased at around 27.0 °C in nano PE clothing. The post-trial mean skin temperature was increased by 1.29 and 0.92 °C in cotton clothing and nano-porous PE clothing, respectively. It was thus to conclude that the nano-porous PE clothing could prompt radiative body heat dissipation in moderate warm indoor environments and thereby contribute to saving energy.
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| 33. |
- Wang, Faming, et al.
(author)
-
Can the PHS model (ISO7933) predict reasonable thermophysiological responses while wearing protective clothing in hot environments?
- 2011
-
In: Physiological Measurement. - : IOP Publishing. - 0967-3334 .- 1361-6579. ; 32:2, s. 239-249
-
Journal article (pop. science, debate, etc.)abstract
- In this paper, the prediction accuracy of the PHS (predicted heat strain) model on human physiological responses while wearing protective clothing ensembles was examined. Six human subjects (aged 29 ± 3 years) underwent three experimental trials in three different protective garments (clothing thermal insulation Icl ranges from 0.63 to 2.01 clo) in two hot environments (40 °C, relative humidities: 30% and 45%). The observed and predicted mean skin temperature, core body temperature and sweat rate were presented and statistically compared. A significant difference was found in the metabolic rate between FIRE (firefighting clothing) and HV (high visibility clothing) or MIL (military clothing) (p < 0.001). Also, the development of heart rate demonstrated the significant effects of the exposure time and clothing ensembles. In addition, the predicted evaporation rate during HV, MIL and FIRE was much lower than the experimental values. Hence, the current PHS model is not applicable for protective clothing with intrinsic thermal insulations above 1.0 clo. The results showed that the PHS model generated unreliable predictions on body core temperature when human subjects wore thick protective clothing such as firefighting clothing (Icl > 1.0 clo). The predicted mean skin temperatures in three clothing ensembles HV, MIL and FIRE were also outside the expected limits. Thus, there is a need for further extension for the clothing insulation validation range of the PHS model. It is recommended that the PHS model should be amended and validated by individual algorithms, physical or physiological parameters, and further subject studies.
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| 34. |
- Wang, Faming
(author)
-
Clothing Evaporative Resistance: Its Measurements and Application in Prediction of Heat Strain
- 2011
-
Doctoral thesis (other academic/artistic)abstract
- Clothing evaporative resistance is one of the most important inputs for both the modelling and for standards dealing with thermal comfort and heat stress. It might be determined on guarded hotplates, on sweating manikins or even on human subjects. Previous studies have demonstrated that the thermal manikin is the most ideal instrument for testing clothing evaporative resistance. However, the repeatability and reproducibility of manikin wet experiments are not very high for a number of reasons such as the use of different test protocols, manikins with different configurations, and different methods applied for calculation. The overall goals of the research presented were: (1) to examine experimental parameters that cause errors in evaporative resistance and to set up a well-defined test protocol to obtain repeatable data; and (2) to apply the reliable clothing evaporative resistance data obtained from manikin measurements and physiological data acquired from human trials to validate the Predicted Heat Strain (PHS) model (ISO 7933). Most of the calculations on clothing evaporative resistance up until now have been based on manikin temperature rather than fabric skin temperature because the fabric skin temperature was unknown. However, the calculated evaporative resistance has been overestimated because the fabric skin temperature is usually lower than the manikin temperature. This is mainly due to that water evaporation cooling down the fabric skin. In Paper I, the error of using manikin temperature instead of fabric skin temperature for evaporative resistance calculation was examined. In Paper II, a universal empirical equation was developed to predict wet skin temperature based on the total heat loss obtained from the manikin and the controlled manikin temperature. Paper III investigated discrepancy between the two options for the calculation of clothing evaporative resistance and how to select one of them for measurements conducted in a so called isothermal condition. Paper IV studied localised clothing evaporative resistance through an inter-laboratory study. The localised dynamic evaporative resistance caused by air and body movement was examined as well. In addition, reduction factor equations for localised evaporative resistance at each local segment were established. The thermophysiological responses of eight human subjects who wore five different vocational garments in various warm and hot environments were investigated (Paper V and Paper VI). The PHS model was validated by those human trials. Some suggestions on how to revise this model in order to achieve wider applicability were discussed and proposed. The results showed that the prevailing method for the calculation of evaporative resistance can generate an error of up to 35.9% on the boundary air layer’s evaporative resistance Rea. In contrast, it introduced an error of up to 23.7% to the clothing total evaporative resistance Ret. The error was dependent on the value of the clothing intrinsic evaporative resistance Recl. The isothermal condition is the most preferred test condition for measurements of clothing evaporative resistance; the isothermal mass loss method is always the correct option to calculate evaporative resistance. The reduction equations developed for localised clothing evaporative resistance have demonstrated that a total evaporative resistance value provided very limited information for local clothing properties and thus, localised values should be reported. The skin temperatures predicted by the PHS model were greatly overestimated in light clothing and high humidity environments (RH>80%). Similarly, the predicted core temperatures in protective clothing FIRE in warm and hot environments were also largely overestimated. The predicted evaporation rate was always much lower than the observed data. Therefore, a further revision of this model is required. This can be achieved by performing more human subject tests and applying more sensitive mathematical equations.
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| 35. |
- Wang, Faming, et al.
(author)
-
CLOTHING REAL EVAPORATIVE RESISTANCE DETERMINED BY MEANS OF A SWEATING THERMAL MANIKIN: A NEW ROUND-ROBIN STUDY
- 2014
-
In: 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
-
Conference paper (peer-reviewed)abstract
- The previous round-robin (RR) study on clothing evaporative resistance (Ret) has shown that the repeatability and reproducibility of clothing Ret measurements on sweating manikins were rather low. To further examine and enhance the measurement accuracy, a new strict but feasible test protocol was proposed and thoroughly examined in a new round-robin test. Eight laboratories participated in this study and three types of sweating manikins were used. Six clothing ensembles including body mapping cycling wear, light summer workwear, typical spring and autumn clothing for people living in subtropical regions, cold protective clothing and functional Gore-Tex coverall were selected. The measurement repeatability and reproducibility are analysed. The ultimate goal of the RR study is to provide solid support for amending ASTM F2370 standard and/or drafting a new ISO/EN standard.
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| 36. |
- Wang, Faming, et al.
(author)
-
Coastal blue carbon in China as a nature-based solution toward carbon neutrality
- 2023
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In: INNOVATION. - 2666-6758. ; 4:5
-
Research review (peer-reviewed)abstract
- To achieve the Paris Agreement, China pledged to become "Carbon Neutral" by the 2060s. In addition to massive decarbonization, this would require significant changes in ecosystems toward negative CO2 emissions. The ability of coastal blue carbon ecosystems (BCEs), including mangrove, salt marsh, and seagrass meadows, to sequester large amounts of CO2 makes their conservation and restoration an important "nature-based solution (NbS)" for climate adaptation and mitigation. In this review, we examine how BCEs in China can contribute to climate mitigation. On the national scale, the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha, including over 75% as unvegetated tidal flats. The annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year(-1) , of which most occurs in salt marshes and tidal flats. The lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year(-1) along the Chinese coastline. Conservation and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of $32,000 ha(-1) year(-1). The potential practices and technologies that can be implemented in China to improve BCE C sequestration, including their constraints and feasibility, are also outlined. Future directions are suggested to improve blue carbon estimates on aerial extent, carbon stocks, sequestration, and mitigation potential. Restoring and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.
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| 37. |
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| 38. |
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| 39. |
- Wang, Faming
(author)
-
Comparisons of Thermal and Evaporative Resistances of Kapok Coats and Traditional Down Coats
- 2010
-
In: Fibres & Textiles in Eastern Europe. - 1230-3666. ; 18:1, s. 75-78
-
Journal article (peer-reviewed)abstract
- The main aim of this paper is to contribute to finding a good solution to the ethical problem of live plucking. The use of new eco-environmental kapok fibres as a coat filler substitute for traditional duckling down was reported. The physical structures of kapok fibre were studied by scanning electron microscopy (SEM). The thermal and evaporative resistance properties of twelve sets of traditional duckling down coats and kapok coats were measured and compared using a novel sweating thermal manikin called "Walter". The results showed that there are no significant statistical differences in thermal and evaporative resistances among traditional duckling down coats and kapok coats. It was also found that there is the best mix rate of material and air trapped inside, which provides the best thermal resistance for the coat. Finally, we proposed that kapok fibres be used as a coat filling to lower the product price. Most importantly, the use of kapok fibre results in as good thermal and evaporative resistances of a coat as with traditional duckling down.
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| 40. |
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| 41. |
- Wang, Faming, et al.
(author)
-
Determination of Clothing Evaporative Resistance on a Sweating Thermal Manikin in an Isothermal Condition: Heat Loss Method or Mass Loss Method?
- 2011
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In: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 1475-3162. ; 55, s. 775-783
-
Journal article (peer-reviewed)abstract
- This paper addresses selection between two calculation options, i.e heat loss option and mass loss option, for thermal manikin measurements on clothing evaporative resistance conducted in an isothermal condition (Tmanikin = Ta = Tr). Five vocational clothing ensembles with a thermal insulation range of 1.05–2.58 clo were selected and measured on a sweating thermal manikin ‘Tore’. The reasons why the isothermal heat loss method generates a higher evaporative resistance than that of the mass loss method were thoroughly investigated. In addition, an indirect approach was applied to determine the amount of evaporative heat energy taken from the environment. It was found that clothing evaporative resistance values by the heat loss option were 11.2–37.1% greater than those based on the mass loss option. The percentage of evaporative heat loss taken from the environment (He,env) for all test scenarios ranged from 10.9 to 23.8%. The real evaporative cooling efficiency ranged from 0.762 to 0.891, respectively. Furthermore, it is evident that the evaporative heat loss difference introduced by those two options was equal to the heat energy taken from the environment. In order to eliminate the combined effects of dry heat transfer, condensation, and heat pipe on clothing evaporative resistance, it is suggested that manikin measurements on the determination of clothing evaporative resistance should be performed in an isothermal condition. Moreover, the mass loss method should be applied to calculate clothing evaporative resistance. The isothermal heat loss method would appear to overestimate heat stress and thus should be corrected before use.
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| 42. |
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| 43. |
- Wang, Faming, et al.
(author)
-
Development and Validation of an Empirical Equation to Predict Sweating Skin Surface Temperature for Thermal Manikins
- 2010
-
In: Textile Bioengineering and Informatics Symposium Proceedings. - 1942-3438. ; 1-3, s. 1213-1218
-
Conference paper (peer-reviewed)abstract
- Thermal manikins are useful tools to study the clothing comfort and environmental ergonomics. The simulation of sweating can be achieved by putting a highly wicking stretchable knit fabric “skin” on top of the manikin. However, the addition of such a fabric skin makes it is difficult to accurately measure the skin surface temperature. Moreover, it takes considerable amount of time to measure the fabric skin surface temperature for each test. At present the attachment of temperature sensors to the wet fabric skin is still a challenge. The distance of the sensors to the fabric skin could significantly influence the temperature and relative humidity values of the wet skin surface. Hence, we conducted an intensive skin study on a dry thermal manikin to investigate the relationships among the nude manikin surface temperature, heat losses and the fabric skin surface temperature. An empirical equation was developed and validated on the thermal manikin "Tore" at Lund University. The empirical equation at ambient temperature 34 oC is Tsk =34.00- 0.0103HL. This equation can be used to enhance the prediction accuracy on the sweating skin surface temperature and the calculation of clothing evaporative resistance.
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| 44. |
- Wang, Faming, et al.
(author)
-
Development and validation of an empirical equation to predict wet fabric skin surface temperature of thermal manikins
- 2010
-
In: Journal of Fiber Bioengineering and Informatics. - : Textile Bioengineering and Informatics Society. - 1940-8676 .- 2617-8699. ; 3:1, s. 9-15
-
Journal article (peer-reviewed)abstract
- Thermal manikins are useful tools to study clothing comfort and environmental ergonomics. The simulation of sweating can be achieved by putting a highly wicking stretchable knit fabric “skin” on top of the manikin. However, the addition of such a fabric skin makes it difficult to accurately measure the skin surface temperature. Moreover, it takes considerable amount of time to measure the fabric skin surface temperature at each test. At present the attachment of temperature sensors to the wet fabric skin is still a challenge. The distance of the sensors to the fabric skin could significantly influence the temperature and relative humidity values of the wet skin surface. Hence, we conducted an intensive skin study on a dry thermal manikin to investigate the relationships among the nude manikin surface temperature, heat losses and the fabric skin surface temperature. An empirical equation was developed and validated on the thermal manikin „Tore‟ at Lund University. The empirical equation at an ambient temperature 34.0 ºC is Tsk =34.00-0.0103HL. This equation can be used to enhance the prediction accuracy of wet fabric skin surface temperature and the calculation of clothing evaporative resistance.
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| 45. |
- Wang, Faming, et al.
(author)
-
Development and validity of a universal empirical equation to predict skin surface temperature on thermal manikins
- 2010
-
In: Journal of Thermal Biology. - : Elsevier BV. - 0306-4565. ; 35:4, s. 197-203
-
Journal article (pop. science, debate, etc.)abstract
- Clothing evaporative resistance is an important input in thermal comfort models. Thermal manikin tests give the most accurate and reliable evaporative resistance values for clothing. The calculation methods of clothing evaporative resistance require the sweating skin surface temperature (i.e., options 1 and 2). However, prevailing calculation methods of clothing evaporative resistance (i.e., options 3 and 4) are based on the controlled nude manikin surface temperature due to the sensory measurement difficulty. In order to overcome the difficulty of attaching temperature sensors to the wet skin surface and to enhance the calculation accuracy on evaporative resistance, we conducted an intensive skin study on a thermal manikin ‘Tore’. The relationship among the nude manikin surface temperature, the total heat loss and the wet skin surface temperature in three ambient conditions was investigated. A universal empirical equation to predict the wet skin surface temperature of a sweating thermal manikin was developed and validated on the manikin dressed in six different clothing ensembles. The skin surface temperature prediction equation in an ambient temperature range between 25.0 and 34.0 °C is Tsk=34.0–0.0132HL. It is demonstrated that the universal empirical equation is a good alternative to predicting the wet skin surface temperature and facilitates calculating the evaporative resistance of permeable clothing ensembles. Further studies on the validation of the empirical equation on different thermal manikins are needed however.
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| 46. |
- Wang, Faming, et al.
(author)
-
Development of Empirical Equations to Predict Sweating Skin Surface Temperature for Thermal Manikins in Warm Environments.
- 2010
-
In: ; , s. 1-5
-
Conference paper (peer-reviewed)abstract
- Clothing evaporative resistance is one of the most important parameters for clothing comfort. The clothing evaporation resistance can be measured on a sweating guarded hotplate, a sweating thermal manikin or a human subject. The sweating thermal manikin gives the most accurate value on evaporative resistance of the whole garment ensemble compared to the other two methods. The determination of clothing evaporative resistance on a thermal manikin requires sweating simulation. This can be achieved by either a pre-wetted fabric skin on top of the manikin (TORE), or a waterproof but permeable Gore-tex skin filled with water inside. The addition of a fabric skin can introduce a temperature difference between the manikin surface and the sweating skin surface. However, calculations on clothing evaporative resistance have often been based on the thermal manikin surface temperature. A previous study showed that the temperature differences can cause an error up to 35.9 % on the clothing evaporative resistance. In order to reduce such an error, an empirical equation to predict the skin surface temperature might be helpful. In this study, a cotton knit fabric skin and a Gore-tex skin were used to simulate two types of sweating. The cotton fabric skin was rinsed with tap water and centrifuged in a washing machine for 4 seconds to ensure no water drip. A Gore-tex skin was put on top of the pre-wetted cotton skin on a dry heated thermal manikin ‘Tore’ in order to simulate senseless sweating, similar to thermal manikins ‘Coppelius’ and ‘Walter’. Another simulation involved the pre-wetted fabric skin covered on top of the Gore-tex skin in order to simulate sensible sweating. This type of sweating simulation can be widely found on many thermal manikins worldwide, e.g. ‘Newton’. Six temperature sensors (Sensirion Inc, Switzerland) were attached on six sites of the skin outer surface by white thread rings to record the skin surface temperature. Twelve skin tests for each skin combination were performed at three different ambient temperatures: 34, 25 and 20 oC. Two empirical equations to predict the skin surface temperature were developed based on the mean manikin surface temperature, mean fabric skin surface temperature and the total heat loss. The prediction equations for the senseless sweating and sensible sweating on the thermal manikin ‘Tore’ were Tsk=34.0-0.0146HL and Tsk=34.0-0.0190HL, respectively. Further study should validate these two empirical equations, however.
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| 47. |
- Wang, Faming, et al.
(author)
-
Does PHS Model Predict Acceptable Skin and Core Temperatures While Wearing Protective Clothing.
- 2010
-
In: ; , s. 1-5
-
Conference paper (peer-reviewed)abstract
- Mathematical modeling is very important when experimental settings with human subjects are restricted to thermal limits necessary to protect the individual. The predicted heat strain (PHS) model has been published AS ISO 7933 for about six years. It describes a method for predicting the sweat rate and internal core temperature that the human body will develop in response to the working conditions. The PHS model was developed based on thousands of laboratory and field experiments collected from eight European laboratories. However, most of the laboratory and field tests were performed on human subjects with light clothing ensembles (0.38±0.34 clo < Icl < 0.77±0.18 clo). The prediction of physiological responses while human wearing highly insulating protective clothing might be weak. In order to check the prediction accuracy of current PHS model while using protective clothing, we conducted totally series of human subject tests at a simulated hot environment. The results of 18 tests involving the high visibility (HV), military (MIL) and firefighting (FIRE) clothing are reported here. Six human subjects were asked to walk on a treadmill at 4.5 km/h at 40 oC for 70 min. Two humidity levels were chosen: 2 kPa (RH = 27 %) and 3 kPa (RH = 41 %) depending on the garment. The rectal temperature, skin temperature, heart rate and metabolic rate were measured. The clothing and the subjects were weighed before and after the exposure in order to calculate the sweat and evaporation rate. The observed and predicted rectal temperatures and mean skin temperatures were compared. The PHS model failed to predict the final rectal temperature in FIRE and the predicted estimate was 1.83 oC higher than the observed value after 63-min exposure. The predicted curve showed a much deeper linear increase during the whole exercise. None of the predicted mean skin temperatures during the three testing scenarios were accurately predicted. The PHS model was consistently providing conservative mean skin temperature evaluations. The predicted curve in HV and MIL showed a much shallower increase during the early portion of the exposure and plateaued at temperatures lower than ever achieved by the subjects. The observed sweat rates were 556±110 g/h in HV, 717±200 g/h in MIL, and 834±274 g/h in FIRE. There was no significant difference between the predicted total sweat values and the experimental data (P=0.073). In summary, the PHS model produce prediction of core temperature which has an unacceptable error when human wore thick protective clothing. The weak prediction on the mean skin temperature in HV and MIL was in agreement with the empirical prediction equation in the source codes has the poorest and lowest correlation when a clothed human subject exercised at the humidity level above 2 kPa. It is therefore recommended that the PHS model should be amended to development and validated by manipulation of individual algorithms or physical (or physiological) parameters.
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| 48. |
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| 49. |
- Wang, Faming, et al.
(author)
-
Effect of Different Fabric Skin Combinations on Predicted Sweating Skin Temperature of a Thermal Manikin
- 2010
-
In: Proceedings Of The Second International Conference On Advanced Textile Materials & Manufacturing Technology. - 9787308079587 ; , s. 184-186
-
Conference paper (peer-reviewed)abstract
- In this study, a knit cotton fabric skin and a Gore-tex skin were used to simulate two sweating methods. The Gore-tex skin was put on top of the pre-wetted knit cotton skin on a dry heated thermal manikin 'Tore' to simulate senseless sweating, similar to thermal manikins 'Coppelius' and 'Walter'. Another simulation involved the pre-wetted fabric skin covered on top of the Gore-tex skin in order to simulate sensible sweating. This type of sweating simulation can be widely found on many thermal manikins worldwide, e.g. 'Newton'. Two empirical equations to predict the wet skin surface temperature were developed based on the mean manikin surface temperature, mean fabric skin surface temperature and the total heat loss. The prediction equations for the senseless sweating and sensible sweating on the thermal manikin 'Tore' were T-sk=34.05-0.0193HL and T-sk=34.63-0.0178HL, respectively. It was found that the Gore-tex skin limits moisture evaporation and the predicted fabric skin temperature was greater than that in the G+C skin combination. Further study should validate those two empirical equations, however.
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| 50. |
- Wang, Faming, et al.
(author)
-
Effect of temperature difference between manikin and wet fabric skin surfaces on clothing evaporative resistance: how much error is there?
- 2012
-
In: International Journal of Biometeorology. - : Springer Science and Business Media LLC. - 1432-1254 .- 0020-7128. ; 56, s. 177-182
-
Journal article (peer-reviewed)abstract
- Clothing evaporative resistance is one of the inherent factors that impede heat exchange by sweating evaporation. It is widely used as a basic input in physiological heat strain models. Previous studies showed a large variability in clothing evaporative resistance both at intra-laboratory and inter-laboratory testing. The errors in evaporative resistance may cause severe problems in the determination of heat stress level of the wearers. In this paper, the effect of temperature difference between the manikin nude surface and wet textile skin surface on clothing evaporative resistance was investigated by both theoretical analysis and thermal manikin measurements. It was found that the temperature difference between the skin surface and the manikin nude surface could lead to an error of up to 35.9% in evaporative resistance of the boundary air layer. Similarly, this temperature difference could also introduce an error of up to 23.7% in the real clothing total evaporative resistance (R ( et_real ) < 0.1287 kPa m(2)/W). Finally, it is evident that one major error in the calculation of evaporative resistance comes from the use of the manikin surface temperature instead of the wet textile fabric skin temperature.
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