High-Performance Apparel and Wearable Devices for Hot Environments

2019 ◽  
Vol 10 (1) ◽  
pp. 1-14
Author(s):  
Radostina A. Angelova
Keyword(s):  
Human Body ◽  
High Performance ◽  
Heat Dissipation ◽  
Wearable Devices ◽  
The Body ◽  
Hot Environment ◽  
Active Protection ◽  
Thermoregulatory System ◽  
Hot Environments ◽  
Body Heat

Smart and intelligent textiles together with wearable devices for cooling the human body assure active protection of the human body in a hot environment. The purpose of this article is to present the recent inventions in the field of wearable technologies and high-performance apparel that helps the thermophysiological comfort of people in high-temperature environments. The work of the thermoregulatory system when the body heat storage is higher than the heat dissipation from the body to the environment is presented together with experimental results from thermograms during physical exercise. High-performance textiles, used in sports apparel, are analyzed in terms of their ability to cool the human body during high metabolic activity. Wearable devices for helping the thermophysiological comfort in the hot are also discussed.

scholarly journals Human body heat for powering wearable devices: From thermal energy to application

2017 ◽  
Vol 131 ◽  
pp. 44-54 ◽  
Author(s):  
Moritz Thielen ◽  
Lukas Sigrist ◽  
Michele Magno ◽  
Christofer Hierold ◽  
Luca Benini
Keyword(s):  
Thermal Energy ◽  
Human Body ◽  
Wearable Devices ◽  
Body Heat

Wearable Technologies for Helping Human Thermophysiological Comfort

2018 ◽  
pp. 203-231
Author(s):  
Radostina A. Angelova
Keyword(s):  
State Of The Art ◽  
Wearable Devices ◽  
The State ◽  
The Body ◽  
Cold Environment ◽  
Human Comfort ◽  
Wearable Technologies ◽  
Thermoregulatory System ◽  
Intelligent Clothing

The thermophysiological comfort is one of the aspects of the human comfort. It is related to the thermoregulatory system of the body and its reactions to the temperature of the surrounding air, activity and clothing. The aim of the chapter is to present the state of the art in the wearable technologies for helping the human thermophysiological comfort. The basic processes of body's thermoregulatory system, the role of the hypothalamus, the reactions of the body in hot and cold environment, together with the related injuries, are described. In the second part of the chapter smart and intelligent clothing, textiles and accessories are presented together with wearable devices for body's heating/cooling.

Clothing sets with thermoregulation function for mine rescuers

2019 ◽  
Vol 574 (7) ◽  
pp. 21-25
Author(s):  
Krzysztof Łężak ◽  
Grażyna Bartkowiak ◽  
Agnieszka Greszta ◽  
Anna Dąbrowska ◽  
Sylwia Krzemińska ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Ad Hoc ◽  
Cooling System ◽  
Heat Stroke ◽  
Climatic Conditions ◽  
The Body ◽  
Hot Environment ◽  
Additional Equipment ◽  
Extreme Hazards ◽  
Change Material

Mine rescuers’ work is associated with many extreme hazards, including difficult climatic conditions. At the same time, the clothing and cooling systems that they use are still too ineffective in terms of dissipating excess heat from the body, which sometimes leads to overheating and consequent death of a rescuer due to heat stroke. These factors constituted an impulse to undertake work towards the development of new, effective in terms of cooling and protective properties, clothing sets for mine rescuers. This publication presents two alternative clothing sets developed in the RESCLO project, made up of outer protective clothing, used along with one of the two underwear variants, ie. underwear with inserts with phase change material (PCM) or underwear with air-fed cooling system from the air receiver. These solutions ensure compatibility with the additional equipment of the rescuer and provide the possibility of ad hoc configuration of clothing sets depending on the conditions of the action and the threats. Laboratory tests have shown that depending on the tested variant, the thermoregulatory solutions used allow for heat dissipation from the rescuer's body at the level of up to 30 W/m2, which will have a positive effect on the safety of mine rescuers during the operation and extend their safe working time in the underground hot environment.

Heat storage regulation in exercise during thermal transients

1976 ◽  
Vol 40 (3) ◽  
pp. 384-392 ◽  
Author(s):  
P. Chappuis ◽  
P. Pittet ◽  
E. Jequier
Keyword(s):  
Heat Storage ◽  
Mean Value ◽  
The Body ◽  
Mean Body Temperature ◽  
Ambient Temperatures ◽  
Thermal Transients ◽  
Thermoregulatory System ◽  
Body Heat ◽  
Rest And Exercise

Rate of heat storage (S) was measured by using direct and indirect calorimetry simultaneously in 11 subjects during rest and exercise at three ambient temperatures (Ta of 20, 25, and 30 degrees C), and at two work intensities (40 and 90 W). At rest, the mean value of S was -64.9 W at 20 degrees C, -26.1 W at 25 degrees C, and +9.9 W at 30 degrees C. After 50 min of exercise at 40 or 90 W, S tended toward zero at the three ambient temperatures. This indicates that thermal equilibrium was reached. In addition, at the end of the exercise periods total heat losses (R + C + E) measured at a Ta of 20, 25, and 30 degrees C were similar, i.e., independent of Ta. During the thermal transients and the steady state of exercise, the calorimetric method allows immediate measurement of S to be made, since all the physical terms of the body heat balance equation are determined. The changes in mean body temperature (delta Tb) measured by thermometry showed a delay of 5–10 min when compared with delta Tb measured by calorimetry. Thus, determination of delta Tb by thermometry is not directly applicable during thermal transients, unless the observed delay is taken into account. Our results also support the concept that Tb may be the regulated variable of the thermoregulatory system, since we obtained a very significant and uniform correlation between Esk and delta Tb at the three Ta and the two work intensities which were studied.

Powering Healthcare IoT Sensors-Based Triboelectric Nanogenerator

2020 ◽  
pp. 29-51
Author(s):  
Saeed Ahmed Khan ◽  
Shamsuddin Lakho ◽  
Ahmed Ali ◽  
Abdul Qadir Rahimoon ◽  
Izhar Hussain Memon ◽  
...  
Keyword(s):  
Human Body ◽  
Pressure Sensors ◽  
Wearable Devices ◽  
Temperature Sensors ◽  
The Body ◽  
Body Motion ◽  
Triboelectric Nanogenerator ◽  
Self Powered ◽  
Fitness Tracking ◽  
Triboelectric Nanogenerators

Most of the emerging electronic devices are wearable in nature. However, the frequent changing or charging the battery of all wearable devices is the big challenge. Interestingly, with those wearable devices that are directly associated with the human body, the body can be used in transferring or generating energy in a number of techniques. One technique is triboelectric nanogenerators (TENG). This chapter covers different applications where the human body is used as a triboelectric layer and as a sensor. Wearable TENG has been discussed in detail based on four basic modes that could be used to monitor the human health. In all the discussions, the main focus is to power the wearable healthcare internet of things (IoT) sensor through human body motion based on self-powered TENG. The IoT sensors-based wearable devices related to human body can be used to develop smart body temperature sensors, pressure sensors, smart textiles, and fitness tracking sensors.

scholarly journals Impact of airflow on body cooling in exercise: an exploratory study

2021 ◽  
Vol 38 (5) ◽  
pp. 261-268
Author(s):  
Pedro H. Nogueira ◽  
Alisson G. da Silva ◽  
Samuel A. Oliveira ◽  
Manuel Sillero-Quintana ◽  
João C. Marins
Keyword(s):  
Repeated Measures ◽  
Heat Dissipation ◽  
Flow Speed ◽  
The Body ◽  
Upper Body ◽  
Moderate Intensity ◽  
Thermal Camera ◽  
Body Cooling ◽  
Relationship Of ◽  
Body Heat

Objective: To analyze the body heat dissipation by thermography during indoor running treadmill with different airflow conditions. Materials and method: Nine male participants (23.0±2.5 years old) underwent three 45-minute moderate-intensity running sessions (60-70% reserve heart rate) on a treadmill. At each session, a different experimental condition was applied in a crossover design: without airflow (NF), and with low (LF) and high airflow (HF) generated by a fun. Thermograms were obtained with a thermal camera before exercise, during (every 10 minutes), and after exercise. Skin temperature (Tsk) was measured on regions of interest of the upper body: pectoral, brachial biceps, and upper back. A repeated measures ANOVA was used to compare Tsk over time and between conditions, considering p<0.05 as statistically significant. Results: In pectoral and brachial biceps, LF and HF conditions provided greater reductions in Tsk at all moments when compared to the NF (p<0.05). There was a higher reduction in Tsk to the HF vs LF in biceps at 30, 40, and 45 min during exercise (p<0.05). In the upper back, Tsk remained below baseline at all moments during exercise only in the HF condition (p<0.05). In NF and LF conditions, Tsk returned to baseline at 30 min during exercise (p>0.05). Conclusion: The frontal wind flow enhances body heat dissipation during moderate-intensity running in the pectoral, brachial biceps, and upper back, with a direct relationship of flow speed and Tsk reduction during exercise.

scholarly journals Experimental Study on the Use of Thermoelectric Generators in Harvesting Human Body Heat

2018 ◽  
Vol 7 (4.35) ◽  
pp. 264
Author(s):  
N. Rosli ◽  
H. Mohamed
Keyword(s):  
Body Temperature ◽  
Human Body ◽  
Electrical Energy ◽  
The Body ◽  
Output Resistance ◽  
Running Activity ◽  
Humid Region ◽  
Human Body Temperature ◽  
Different Temperatures ◽  
Body Heat

The objective of this work is to investigate the potential use of a thermoelectric generator (TEG) in harvesting human body heat at four body locations namely forehead, wrist, palm and calf for different human activities in Malaysia. Important parameters for this experiment are human body temperature, room temperature, output voltage, output resistance and output power. A healthy male and female perform a series of activities including resting, walking and running for 10 minutes in an indoor setting. Results indicate the relevant effects of temperature and movement on producing power from human body heat. Different parts of the body have different temperatures, thus creating different output powers. Results show that as the movement increases, the human body temperature and the amount of energy harvested also increase. It is also observed that forehead provides the highest amount of power generated during running activity. When the body temperature is above 35 °C, the TEG can generate power more than 5.0 mW. The highest power generated during the experiment is 9.5 mW. Even though Malaysia is known as a hot and humid region, TEGs can be feasibly utilized as a wearable device that converts human heat energy into electrical energy.

SECOND LAW OF THERMODYNAMICS AND HUMAN BODY

2011 ◽  
Vol 10 (1-2) ◽  
pp. 88 ◽  
Author(s):  
C. E. K. Mady ◽  
M. S. Ferreira ◽  
J. I. Yanagihara ◽  
S. Oliveira Jr ◽  
P. H. N. Saldiva
Keyword(s):  
Human Body ◽  
Second Law Of Thermodynamics ◽  
Exergy Efficiency ◽  
The Body ◽  
Human Model ◽  
Main Concern ◽  
Elliptical Cross ◽  
Energy And Exergy ◽  
Thermoregulatory System ◽  
Exergy Transfer

Exergy analysis was applied to assess the energy conversion processes that take place in the human body, aiming at developing correlations of the destroyed exergy and exergy efficiency with the constants of the thermoregulatory system of a human model. Moreover the main concern of the present work was obtaining the exergy behavior of a healthy person. The analysis was applied to a model composed of 15 cylinders with elliptical cross section representing: head, neck, trunk, arms, forearms, hands, thighs, legs, and feet. For each cylinder a combination of the following tissues was considered: skin, fat, muscle, bone, brain, viscera, lung, and heart. From this model it was possible to obtain the energy and exergy transfer to the environment associated with radiation, convection, vaporization and respiration. It was also possible to calculate the energy and exergy variation of the body over time. Results indicate that the energy transfer to the environment is one order of magnitude larger than the exergy transfer and both have different trends. Simulations were carried out for different constants of the thermoregulatory system, and the results that gave the thermal response close to experimental responses of the human body, are in a point near to the minimum exergy destruction and maximum exergy efficiency.

scholarly journals Biomonitoring and Elimination of Perfluorinated Compounds and Polychlorinated Biphenyls through Perspiration: Blood, Urine, and Sweat Study

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Stephen J. Genuis ◽  
Sanjay Beesoon ◽  
Detlef Birkholz
Keyword(s):  
Polychlorinated Biphenyls ◽  
Human Body ◽  
High Performance ◽  
Effective Means ◽  
Perfluorinated Compounds ◽  
The Body ◽  
Western World ◽  
Human Organism ◽  
Liquid Chromatography Tandem Mass ◽  
Persistent Contaminants

Perfluorinated compounds (PFCs) are man-made organofluorine chemicals manufactured and marketed for their stain-resistant properties. Polychlorinated biphenyls (PCBs) are anthropogenic organochlorine compounds previously used in various industrial and chemical applications prior to being banned in the Western world in the 1970s. Both PFCs and PCBs are persistent contaminants within the human organism and both have been linked to adverse health sequelae. Data is lacking on effective means to facilitate clearance of PFCs and PCBs from the body. Methods. Blood, urine, and sweat were collected from 20 individuals (10 healthy participants and 10 participants with assorted health problems) and analyzed for PFCs and PCBs using high performance liquid chromatography tandem mass spectrometry. Results. Some individual PCB congeners, but not all, were released into sweat at varying concentrations. None of the PFCs found in serum testing appeared to be excreted efficiently into perspiration. Conclusions. Induced perspiration may have some role in facilitating elimination of selected PCBs. Sweat analysis may be helpful in establishing the existence of some accrued PCBs in the human body. Sweating does not appear to facilitate clearance of accrued PFHxS (perfluorohexane sulfonate), PFOS (perfluorooctane sulfonate), or PFOA (perfluorooctanoic acid), the most common PFCs found in the human body.

Changes of thermal balance induced by passive heating in resting man

1975 ◽  
Vol 38 (2) ◽  
pp. 294-299 ◽  
Author(s):  
R. Henane ◽  
J. Bittel
Keyword(s):  
Rectal Temperature ◽  
Heat Dissipation ◽  
Heat Storage ◽  
Heat Content ◽  
Skin Surface ◽  
Thermal Balance ◽  
The Body ◽  
Heat Acclimatization ◽  
Increased Sensitivity ◽  
Body Heat

Heat acclimatization has been induced in 12 resting healthy men by 90-min exposure to 45C dry bulb and 24% relative humidity for 9 successive days. The most significant results ovserved were 1) increased sensitivity of sweating with marked quickening of sweat measured, 2) decreased rate of body heat storage associated with a lower rectal temperature at end of exposure, as follows: 14.07 plus or minus 1.58 Wtimeshtimeskg-1 before and 9.39 plus or minus 1.69 afterward for body heat storage; 37.55 plus or minus 0.15C before and 36.99 plus or minus 0.24C afterward for rectal temperature. In contrast, no significant changes were observed in the final sweat rates, mean skin temperatures, or the heat conductance between the body interior and skin surface. The quickness of the heat dissipation process caused by both increased sensitivity of sweating and lower internal body temperature is the major factor in achieving a thermal balance and a decreased body heat content after acclimatization.

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