scholarly journals Automatic Control of Human Thermal Comfort by a Liquid-Cooled Garment

1980 ◽  
Vol 102 (2) ◽  
pp. 155-161 ◽  
Author(s):  
L. H. Kuznetz
Keyword(s):  
Thermal Comfort ◽  
Cooling Water ◽  
Thermal Control ◽  
Coolant Temperature ◽  
Space Suit ◽  
Human Thermal Comfort ◽  
Wide Range ◽  
The Difference ◽  
Body Heat ◽  
Human Thermoregulation

Astronauts utilize water cooling in a liquid-cooled garment to maintain thermal comfort during extravehicular activities (EVA’s). In the Apollo and Skylab Programs, manual control of the cooling water was a necessary operation to ensure proper control of body heat storage for the EVA crewman. The development of an automatic thermal control system would be a valuable asset to the conduct of EVA, relieving the crewman of a task that can interfere with his EVA objectives. An analytical model of human thermoregulation was used to develop the equations governing the operation of such an automatic controller. A series of tests verified the feasibiliy of a controller utilizing only a measurement of the difference in coolant temperature into and out of the astronaut’s liquid-cooled garment and an estimate of environmental heat loss to maintain the proper crewman thermal balance. Three test subjects performed over a wide range of metabolic rates, and the crewman heat balance was maintained well within allowable medical limits. This study demonstrates the use of a mathematical model to generate previously unknown physiological relationships between human thermal comfort and liquid cooled garment performance. In so doing, it quantitates physiological parameters that are difficult to relate directly by experiment. Index terms: body temperature regulation, space suit cooling, temperature control, human thermoregulation.

A review of noteworthy/major innovations in wearable clothing for thermal and moisture management from material to fabric structure

2021 ◽  
pp. 004051752110277
Author(s):  
Hafiz Muhammad Kaleem Ullah ◽  
Joseph Lejeune ◽  
Aurélie Cayla ◽  
Mélanie Monceaux ◽  
Christine Campagne ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
The Body ◽  
Innovative Strategies ◽  
Individual Level ◽  
Thermal Range ◽  
Moisture Management ◽  
Wide Range ◽  
The Individual ◽  
Air Conditioning Systems ◽  
Body Heat

The human body exchanges heat through the environment by various means, such as radiation, evaporation, conduction, and convection. Thermo-physiological comfort is associated with the effective heat transfer between the body and the atmosphere, maintaining the body temperature in a tolerable thermal range (36.5–37.5ºC). In order to ensure comfort, the body heat must be preserved or emitted, depending on external conditions. If the body heat is not properly managed, it can cause hyperthermia, heatstroke, and thermal discomfort. Conventionally, heating, ventilation, and air conditioning systems are used to provide comfort. However, they require a huge amount of energy, leading to an increase in global warming, and are limited to indoor applications. In recent decades, scientists across the world have been working to provide thermal comfort through wearable innovative textiles. This review article presents recent innovative strategies for moisture and/or thermal management at the material, filament/fiber, yarn, and fabric scales. It also summarizes the passive/active textile models for comfort. Integrating electrical devices in garments can rapidly control the skin temperature, and is dynamic and useful for a wide range of environmental conditions. However, their use can be limited in some situations due to their bulky design and batteries, which must be frequently recharged. Furthermore, adaptive textiles enable the wearer to maintain comfort in various temperatures and humidity without requiring batteries. Using these wearable textiles is convenient to provide thermal comfort at the individual level rather than controlling the entire building temperature.

Model of Human/Liquid Cooling Garment Interaction for Space Suit Automatic Thermal Control

2000 ◽  
Vol 123 (1) ◽  
pp. 114-120 ◽  
Author(s):  
Karen L. Nyberg ◽  
Kenneth R. Diller ◽  
Eugene H. Wissler
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Thermal Comfort ◽  
Control Algorithm ◽  
Thermal Control ◽  
Metabolic Profiles ◽  
Space Suit ◽  
Liquid Cooling ◽  
The Subject ◽  
Cooling Garment

The Wissler human thermoregulation model was augmented to incorporate simulation of a space suit thermal control system that includes interaction with a liquid cooled garment (LCG) and ventilation gas flow through the suit. The model was utilized in the design process of an automatic controller intended to maintain thermal neutrality of an exercising subject wearing a liquid cooling garment. An experimental apparatus was designed and built to test the efficacy of specific physiological state measurements to provide feedback data for input to the automatic control algorithm. Control of the coolant inlet temperature to the LCG was based on evaluation of transient physiological parameters that describe the thermal state of the subject, including metabolic rate, skin temperatures, and core temperature. Experimental evaluation of the control algorithm function was accomplished in an environmental chamber under conditions that simulated the thermal environment of a space suit and transient metabolic work loads typical of astronaut extravehicular activity (EVA). The model was also applied to analyze experiments to evaluate performance of the automatic control system in maintaining thermal comfort during extensive transient metabolic profiles for a range of environmental temperatures. Finally, the model was used to predict the efficacy of the LCG thermal controller for providing thermal comfort for a variety of regimens that may be encountered in future space missions. Simulations with the Wissler model accurately predicted the thermal interaction between the subject and LCG for a wide range of metabolic profiles and environmental conditions and matched the function of the automatic temperature controller for inlet cooling water to the LCG.

scholarly journals Electric Heating Load Forecasting Method Based on Improved Thermal Comfort Model and LSTM

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4525
Author(s):  
Jie Sun ◽  
Jiao Wang ◽  
Yonghui Sun ◽  
Mingxin Xu ◽  
Yong Shi ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Distribution Network ◽  
Influence Factors ◽  
Electric Heating ◽  
Normal Operation ◽  
Human Thermal Comfort ◽  
Heating Load ◽  
The Difference ◽  
Eastern Inner Mongolia ◽  
Thermal Comfort Model

The accuracy of the electric heating load forecast in a new load has a close relationship with the safety and stability of distribution network in normal operation. It also has enormous implications on the architecture of a distribution network. Firstly, the thermal comfort model of the human body was established to analyze the comfortable body temperature of a main crowd under different temperatures and levels of humidity. Secondly, it analyzed the influence factors of electric heating load, and from the perspective of meteorological factors, it selected the difference between human thermal comfort temperature and actual temperature and humidity by gray correlation analysis. Finally, the attention mechanism was utilized to promote the precision of combined adjunction model, and then the data results of the predicted electric heating load were obtained. In the verification, the measured data of electric heating load in a certain area of eastern Inner Mongolia were used. The results showed that after considering the input vector with most relative factors such as temperature and human thermal comfort, the LSTM network can realize the accurate prediction of the electric heating load.

Numerical Simulation of Human Thermal Comfort with Different Thermal Boundary Conditions in Buildings

2014 ◽  
Vol 522-524 ◽  
pp. 1707-1712 ◽  
Author(s):  
Qing Long Peng ◽  
Zhao Hui Qi ◽  
Xia Gan ◽  
Chao Li
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Boundary Condition ◽  
Thermal Comfort ◽  
Human Body ◽  
Thermal Boundary Condition ◽  
Human Thermal Comfort ◽  
The Third ◽  
Thermal Boundary Conditions ◽  
Body Heat

How to use numerical simulation method to analyze human body heat transfer and human thermal comfort is introduced in this paper systematically. Under the same working conditions, numerical simulation of human body heat transfer has been finished based on three thermal boundary conditions, and then the results are compared. The results show that the third thermal boundary condition is better than the first and the second one, which have some problems in simulation and are not good at reflecting the fact on thermal comfort of human body. The third thermal boundary condition which is made to adapt the surrounding flow field automatically can get a more accurate result on calculating the heat transfer of different parts on human body and reflect hot or cool feeling preferably, which proves that the method put forward in this article to research the human body comfort is feasible.

Comparative Effects of High-Tech Visual Scene Displays and Low-Tech Isolated Picture Symbols on Engagement From Students With Multiple Disabilities

2019 ◽  
Vol 50 (4) ◽  
pp. 693-702 ◽  
Author(s):  
Christine Holyfield ◽  
Sydney Brooks ◽  
Allison Schluterman
Keyword(s):  
Language Learning ◽  
Augmentative And Alternative Communication ◽  
Visual Analysis ◽  
Multiple Disabilities ◽  
Visual Scene ◽  
Future Research ◽  
High Tech ◽  
Single Subject ◽  
Wide Range ◽  
The Difference

Purpose Augmentative and alternative communication (AAC) is an intervention approach that can promote communication and language in children with multiple disabilities who are beginning communicators. While a wide range of AAC technologies are available, little is known about the comparative effects of specific technology options. Given that engagement can be low for beginning communicators with multiple disabilities, the current study provides initial information about the comparative effects of 2 AAC technology options—high-tech visual scene displays (VSDs) and low-tech isolated picture symbols—on engagement. Method Three elementary-age beginning communicators with multiple disabilities participated. The study used a single-subject, alternating treatment design with each technology serving as a condition. Participants interacted with their school speech-language pathologists using each of the 2 technologies across 5 sessions in a block randomized order. Results According to visual analysis and nonoverlap of all pairs calculations, all 3 participants demonstrated more engagement with the high-tech VSDs than the low-tech isolated picture symbols as measured by their seconds of gaze toward each technology option. Despite the difference in engagement observed, there was no clear difference across the 2 conditions in engagement toward the communication partner or use of the AAC. Conclusions Clinicians can consider measuring engagement when evaluating AAC technology options for children with multiple disabilities and should consider evaluating high-tech VSDs as 1 technology option for them. Future research must explore the extent to which differences in engagement to particular AAC technologies result in differences in communication and language learning over time as might be expected.

Analysis of the Influence of Age on Human Thermal Comfort

ICCREM 2020 ◽  
2020 ◽  
Author(s):  
Boshuai Dong ◽  
Chunjing Shang ◽  
Ming Tong ◽  
Jianhong Cai
Keyword(s):  
Thermal Comfort ◽  
Human Thermal Comfort

COMBINATORIAL POLYNOMIALLY COMPUTABLE CHARACTERISTICS OF SUBSTITUTIONS AND THEIR PROPERTIES

2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  
Keyword(s):  
Mathematical Expectation ◽  
Point Of View ◽  
Small Range ◽  
Computational Point ◽  
Wide Range ◽  
Bijective Function ◽  
The Difference ◽  
Element Base ◽  
Selection Of

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.

URBAN FACADE GEOMETRY ON OUTDOOR COMFORT CONDITIONS: A REVIEW

2020 ◽  
Vol 4 (1) ◽  
pp. 45
Author(s):  
Elahe Mirabi ◽  
Nasrollahi Nazanin
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Natural Ventilation ◽  
Flow Behavior ◽  
Air Flow ◽  
Urban Geometry ◽  
Wide Range ◽  
Low Energy Buildings ◽  
Outdoor Comfort ◽  
Solar Access

<p>Designing urban facades is considered as a major factor influencing issues<br />such as natural ventilation of buildings and urban areas, radiations in the<br />urban canyon for designing low-energy buildings, cooling demand for<br />buildings in urban area, and thermal comfort in urban streets. However, so<br />far, most studies on urban topics have been focused on flat facades<br />without details of urban layouts. Hence, the effect of urban facades with<br />details such as the balcony and corbelling on thermal comfort conditions<br />and air flow behavior are discussed in this literature review. <strong>Aim</strong>: This<br />study was carried out to investigate the effective factors of urban facades,<br />including the effects of building configuration, geometry and urban<br />canyon’s orientation. <strong>Methodology and Results</strong>: According to the results,<br />the air flow behavior is affected by a wide range of factors such as wind<br />conditions, urban geometry and wind direction. Urban façade geometry<br />can change outdoor air flow pattern, thermal comfort and solar access.<br /><strong>Conclusion, significance and impact study</strong>: In particular, the geometry of<br />the facade, such as indentation and protrusion, has a significant effect on<br />the air flow and thermal behavior in urban facades and can enhance<br />outdoor comfort conditions. Also, Alternation in façade geometry can<br />affect pedestrians' comfort and buildings energy demands.</p>

Generalized Heterodyne Configurations for Photo-induced Force Microscopy

2019 ◽  
Author(s):  
Le Wang ◽  
Devon Jakob ◽  
Haomin Wang ◽  
Alexis Apostolos ◽  
Marcos M. Pires ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Repetition Rate ◽  
Modulation Frequency ◽  
High Harmonic ◽  
Chemical Imaging ◽  
Heterodyne Detection ◽  
Force Microscopy ◽  
Wide Range ◽  
The Difference ◽  
Afm Cantilever

<div>Infrared chemical microscopy through mechanical probing of light-matter interactions by atomic force microscopy (AFM) bypasses the diffraction limit. One increasingly popular technique is photo-induced force microscopy (PiFM), which utilizes the mechanical heterodyne signal detection between cantilever mechanical resonant oscillations and the photo induced force from light-matter interaction. So far, photo induced force microscopy has been operated in only one heterodyne configuration. In this article, we generalize heterodyne configurations of photoinduced force microscopy by introducing two new schemes: harmonic heterodyne detection and sequential heterodyne detection. In harmonic heterodyne detection, the laser repetition rate matches integer fractions of the difference between the two mechanical resonant modes of the AFM cantilever. The high harmonic of the beating from the photothermal expansion mixes with the AFM cantilever oscillation to provide PiFM signal. In sequential heterodyne detection, the combination of the repetition rate of laser pulses and polarization modulation frequency matches the difference between two AFM mechanical modes, leading to detectable PiFM signals. These two generalized heterodyne configurations for photo induced force microscopy deliver new avenues for chemical imaging and broadband spectroscopy at ~10 nm spatial resolution. They are suitable for a wide range of heterogeneous materials across various disciplines: from structured polymer film, polaritonic boron nitride materials, to isolated bacterial peptidoglycan cell walls. The generalized heterodyne configurations introduce flexibility for the implementation of PiFM and related tapping mode AFM-IR, and provide possibilities for additional modulation channel in PiFM for targeted signal extraction with nanoscale spatial resolution.</div>

OVERVIEW OF URBAN HEAT ISLAND (UHI) PHENOMENON TOWARDS HUMAN THERMAL COMFORT

2017 ◽  
Vol 16 (9) ◽  
pp. 2097-2111 ◽  
Author(s):  
Mohanadoss Ponraj ◽  
Yee Yong Lee ◽  
Mohd Fadhil Md Din ◽  
Zainura Zainon Noor ◽  
Kenzo Iwao ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Heat Island ◽  
Human Thermal Comfort ◽  
Urban Heat
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