scholarly journals Concepts and New Implements for Modified Physiologically Equivalent Temperature

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 694 ◽  
Author(s):  
Yung-Chang Chen ◽  
Wei-Nai Chen ◽  
Charles Chou ◽  
Andreas Matzarakis
Keyword(s):  
Urban Climate ◽  
Thermal Conditions ◽  
Physiological Model ◽  
Physiologically Equivalent Temperature ◽  
Slight Variation ◽  
Equivalent Temperature ◽  
Thermal Perception ◽  
Thermal Indices ◽  
Clothing Insulation ◽  
Thermal Risk

Different kinds of thermal indices have been applied in several decades as essential tools to investigate thermal perception, environmentally thermal conditions, occupant thermal risk, public health, tourist attractiveness, and urban climate. Physiologically equivalent temperature (PET) has been proved as a relatively wide applicable thermal indicator above other thermal indices. However, the current practical PET performs a slight variation influenced by changing the humidity and clothing insulation. The improvement of the PET has potentiality for further multi-application as a general and consistent standard to estimate thermal perception and tolerance for different studies. To achieve the above purpose, modified physiologically equivalent temperature (mPET) is proposed as an appropriate indicator according to the new structure and requirements of the thermally environmental ergonomics. The modifications to formulate the mPET are considerably interpreted in the principle of the heat transfer inside body, thermo-physiological model, clothing model, and human-environmental interaction in this study. Specifically, the mPET-model has adopted a semi-steady-state approach to calculate an equivalent temperature refer to an indoor condition as the mPET. Finally, the sensitivity test of the biometeorological variables and clothing impact proves that the mPET has better performance on the humidity and clothing insulation than the original PET.

scholarly journals Comparison of Thermal Comfort between Sapporo and Tokyo—The Case of the Olympics 2020

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 444
Author(s):  
Yuting Wu ◽  
Kathrin Graw ◽  
Andreas Matzarakis
Keyword(s):  
Heat Stress ◽  
Thermal Comfort ◽  
Olympic Games ◽  
Physiologically Equivalent Temperature ◽  
Precipitation Rate ◽  
Equivalent Temperature ◽  
Thermal Indices ◽  
Climate Conditions ◽  
Northern City ◽  
The Olympic Games

Weather and climate conditions can be decisive regarding travel plans or outdoor events, especially for sport events. The Olympic Games 2020, postponed to 2021, will take place in Tokyo at a time which is considered to be the hottest and most humid time of the year. However, a part of the athletic competitions is relocated to the northern city Sapporo. Therefore, it is important to quantify thermal comfort for different occasions and destinations and make the results accessible to visitors and sport attendees. The following analysis will quantify and compare thermal comfort and heat stress between Sapporo and Tokyo using thermal indices like the Physiologically Equivalent Temperature and the modified Physiologically Equivalent Temperature (PET and mPET). The results reveal different precipitation patterns for the cities. While a higher precipitation rate appears in Sapporo during winter, the precipitation rate is higher in Tokyo during summer. PET and mPET exhibit a greater probability of heat stress conditions in Tokyo during the Olympic Games, whereas Sapporo has more moderate values for the same period. The Climate-Tourism/Transfer-Information-Scheme (CTIS) integrates and simplifies climate information and makes them comprehensible for non-specialists. The CTIS of Tokyo illustrates lower suitable conditions for “Heat stress”, “Sunny days” and “Sultriness”. Transferring parts of the athletics competition to a northern city is thus more convenient for athletes, staff members and spectators. Hence, heat stress can be avoided and an acceptable outdoor stay is ensured. Overall, this quantification and comparison of the thermal conditions in Sapporo and Tokyo reveal limitations but also possibilities for the organizers of the Olympic Games. Furthermore it can be used to raise awareness for promoting or arranging countermeasures and heat mitigation at specific events and destinations, if necessary.

Some evidence of a time-varying thermal perception

2021 ◽  
pp. 1420326X2110345
Author(s):  
Marika Vellei ◽  
William O’Brien ◽  
Simon Martinez ◽  
Jérôme Le Dréau
Keyword(s):  
Thermal Comfort ◽  
Energy Savings ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Time Of Day ◽  
Time Varying ◽  
Thermal Perception ◽  
Indoor Thermal Environment ◽  
Human Circadian Rhythm ◽  
Comfort Criteria

Recent research suggests that a time-varying indoor thermal environment can lead to energy savings and contribute to boost buildings' energy flexibility. However, thermal comfort standardization has so far considered thermal comfort criteria as constant throughout the day. In general, very little attention has been given to the ‘ time of day' variable in the context of thermal comfort research. In this paper, we show some evidence of a time-varying thermal perception by using: (1) data from about 10,000 connected Canadian thermostats made available as part of the ‘ Donate Your Data' dataset and (2) about 22,000 samples of complete (objective + ‘ right-here-right-now' subjective) thermal comfort field data from the ASHRAE I and SCATs datasets. We observe that occupants prefer colder thermal conditions at 14:00 and progressively warmer ones in the rest of the day, indistinctively in the morning and evening. Neutral temperature differences between 08:00 and 14:00 and 14:00 and 20:00 are estimated to be of the order of 2°C. We hypothesize that the human circadian rhythm is the cause of this difference. Nevertheless, the results of this study are only based on observational data. Thermal comfort experiments in controlled environmental chambers are required to confirm these findings and to better elucidate the effects of light and circadian timing and their interaction on thermal perception.

Transient Human Thermal Comfort Response in Convective and Radiative Environments

2008 ◽  
Author(s):  
Mohamad Al-Othmani ◽  
Nesreen Ghaddar ◽  
Kamel Ghali
Keyword(s):  
Thermal Comfort ◽  
Thermal Conditions ◽  
Activity Level ◽  
Convective Heating ◽  
Convective System ◽  
Clothing Insulation ◽  
Indoor Space ◽  
Human Thermal Comfort ◽  
Walking Activity ◽  
Local Thermal Comfort

In this work, human transient thermal responses and comfort are studied in non-uniform radiant heating and convective heating environments. The focus was on a change from walking activity of human in outdoor cold environment at high clothing insulation to warm indoor environment at sedentary activity level associated with lower clothing insulation. A transient multi-segmented bioheat model sensitive to radiant asymmetry is used to compare how fast the human body approaches steady state thermal conditions in both radiative and convective warm environments. A space thermal model is integrated with the bioheat model to predict the transient changes in skin and core temperature of a person subject to change in metabolic rate and clothing insulation when entering conditioned indoor space. It was found that overall thermal comfort and neutrality were reached in 6.2 minutes in the radiative environment compared to 9.24 minutes in convective environment. The local thermal comfort of various body segments differed in their response to the convective system where it took more than 19 minutes for extremities to reach local comfort unlike the radiative system where thermal comfort was attained within 7 minutes.

Radiation and thermal effects on polymeric immobilization devices used in patients submitted to radiotherapy

2011 ◽  
Vol 11 (2) ◽  
pp. 101-106
Author(s):  
C. Pereira-Loch ◽  
R. Benavides ◽  
M. Fogliato S. Lima ◽  
B.M. Huerta
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Young’S Modulus ◽  
Thermal Effects ◽  
Young's Modulus ◽  
Thermal Conditions ◽  
Joint Effect ◽  
Hot Water ◽  
Slight Variation ◽  
The Stability

AbstractImmobilization devices in radiotherapy are made of a soft plastic easy to mould when immersed in hot water. Same item is usually used for 6 patients (according to protocol), but at Hospital Sao Jose (HSJ) they have been showing some deformation during the re-utilization process. The latter is the reason for this research where devices were treated with 6 thermal conditions, 6 irradiation procedures and the joint effect of both treatments. DSC, TGA and WAXD indicated devices are made of polycaprolactone (PCL), but no signs of degradation, except a slight variation in crystalinity; however, mechanical properties by means of Young’s modulus steadily increase its values through number of treatments up to a 20%. Activation energy (Ea) obtained by multi-ramps of TGA-Arrhenius evaluated for the most treated samples (6th treatment) indicates that temperature facilitates degradation while irradiation and joint treatments enhance the stability of PCL, apparently by crosslinking.

scholarly journals Thermal Comfort Assessment and Heat-Related Illnesses among Sellers in Periodic Local Markets: A Case Study in Hot and Dry Climate of Iran

2021 ◽  
Author(s):  
Hoda Rahimifard ◽  
Hamidreza Heidari ◽  
Abolfazl Mohamadbeigi ◽  
Ahmad Soltanzadeh ◽  
Mohsen Mahdinia ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Environmental Parameters ◽  
Thermal Conditions ◽  
Tympanic Temperature ◽  
Thermal Indices ◽  
Local Conditions ◽  
Environmental Indices ◽  
Local Markets ◽  
Hot Climate ◽  
Globe Temperature

Background:This study aims to evaluate the thermal conditions of periodic local markets and determine the thermal comfort and sensation of sellers, as well as the prevalence of heat-related diseases in the hot and dry climate of Iran. Methods:In this study, thermal comfort and sensation of 330 sellers from periodic markets in Qom city, a dry and hot climate in Iran, were evaluated. Measurements were performed for 15 days, from July 16 to August 1. To assess environmental thermal condition, wet bulb globe temperature (WBGT) index and discomfort index (DI) were determined, and participants' tympanic temperature was determined to consistency assessment with thermal indices. Finally, the effects of environmental, personal, and working conditions on the prevalence of heat-related diseases among sellers were determined. Results:The environmental indices, including DI and WBGT index, had the most association with heat-related illnesses and tympanic temperature (P<0.05). The sellers perceived the environmental conditions as warm to hot after 1:00 pm. Besides, they expressed an uncomfortable or very uncomfortable situation after 12:00 pm. The findings showed that environmental parameters play a more important role in the prevalence of heat-related diseases and heat strain than individual and occupational factors. Conclusion:The sellers may be at risk of heat stress in outdoor markets in nearly half of the workday in the summer months. Therefore, it is very important that these people receive the necessary training in the prevention of heat illness in order to take appropriate protective measures in accordance with local conditions.

scholarly journals Thermal Sensations of Workers in Light Industry in Summer. A Field Study in Southern England

1955 ◽  
Vol 53 (1) ◽  
pp. 112-123 ◽  
Author(s):  
D. E. Hickish
Keyword(s):  
Technical Assistance ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Thermal Conditions ◽  
Comfort Zone ◽  
Factory Workers ◽  
Thermal Indices ◽  
Light Industry ◽  
Critical Temperatures ◽  
Southern England

SummaryWorkers in factories and a postal sorting office were questioned concerning their subjective thermal sensations, and the replies assessed according to a scale of standard sensations. Measurements of the thermal environment were made concurrently. The investigation was confined to workers engaged in light or sedentary activity during summer months in southern England.The upper limit of the comfort zone is determined in terms of the temperatures at which more than 20% of people questioned experienced thermal discomfort.Discontinuities in the linear relationships between thermal sensation, described on a numerical scale, and the thermal indices of the environment are shown to occur under conditions which suggest the onset of sweating beneath the clothing. The comfort zone is also determined in terms of these critical temperatures.The regression constants relating thermal sensation to thermal conditions are determined, and the optimum conditions for comfort are deduced. The accuracy of prediction of thermal sensation from thermal measurements is examined.The importance of clothing in requirements for thermal comfort is illustrated in two ways. Postal workers wearing regulation uniform were found to require conditions cooler than those required by factory workers wearing clothing of their own choosing. Male and female factory workers were found to require thermal conditions not significantly different, this being attributed to their selection of clothing appropriate to their personal thermal requirements.I am indebted to Prof. G. P. Crowden for granting facilities for this research and for encouragement throughout. Dr T. C. Angus and Dr T. Bedford gave valuable advice, and Mr P. J. Williams rendered technical assistance. The co-operation of the managements and workers at the factories was greatly appreciated.

Detailed analysis of extreme heatwaves in Serbia, South-East Europe

2021 ◽  
Author(s):  
Biljana Basarin ◽  
Tin Lukić ◽  
Tanja Micić Ponjiger
Keyword(s):  
Detailed Analysis ◽  
Heat Wave ◽  
Heat Waves ◽  
Extreme Temperature ◽  
Physiologically Equivalent Temperature ◽  
Daily Maximum ◽  
Maximum Magnitude ◽  
The European Union ◽  
Equivalent Temperature ◽  
Mitigation And Adaptation

&lt;p&gt;A detailed analysis of extreme heatwave events in Serbia from the biometeorological point of view is presented in this study.&amp;#160; For this purpose, the newly developed Heat Wave Magnitude Index daily (HWMId), was used on Physiologically equivalent temperature (PET) for Serbia. A series of daily maximum air temperature, relative humidity, the wind was used to calculate PET for the investigated period 1979&amp;#8211;2019. HWMId is defined as the maximum magnitude of the heatwaves in a year. Here, the heatwave is characterized as 3 consecutive days with maximum PET above the daily threshold for the reference period 1981&amp;#8211;2010. The analysis revealed that during the investigated period the most intensive heat waves occurred in 2007, 2012 and 2015. HWMId values for 2007 were in the range of 8 to 23 indicating extreme heat stress, while for the other two events the values were not as high. Hourly temperatures revealed that the PET values during the day were as high as 55&amp;#176;C. Thus, the mitigation and adaptation to extreme temperature events are of vital importance for humans and their everyday activities. Future investigation should be oriented towards a way to deal with the oppressive heat. Additionally, more research is needed in order to explain and predict these catastrophic events. The main focus of future activities will be on determining the physical causes which lead to the occurrence of extreme heatwaves.&lt;/p&gt;&lt;p&gt;Keywords: Heat Wave Magnitude Index daily, Physiologically equivalent temperature, Serbia, heat waves&lt;/p&gt;&lt;p&gt;Acknowledgment: This research is supported by &lt;strong&gt;EXtremeClimTwin&lt;/strong&gt; project funded from the European Union&amp;#8217;s Horizon 2020 research and innovation programme under grant agreement No 952384&lt;/p&gt;

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